diff --git a/MyExpression.Console/Program.cs b/MyExpression.Console/Program.cs
index cddaf61..dd93d7a 100644
--- a/MyExpression.Console/Program.cs
+++ b/MyExpression.Console/Program.cs
@@ -12,13 +12,16 @@ public class Program
 	{
 		private static void Main(string[] args)
 		{
-			System.Console.Write("Equation: ");
-			var s = System.Console.ReadLine();
-			var p = Polynomial.Parse(s);
-			var e = new PolynomialEquation(p, 1e-8);
-			e.Solve();
-			//System.Console.WriteLine(String.Join(" ", e.AllRoots));
-			System.Console.WriteLine("   Roots: " + String.Join(" ", e.Roots));
+			//System.Console.Write("Equation: ");
+			//var s = System.Console.ReadLine();
+			//System.Console.Write(" Epsilon: ");
+			//var eps = System.Console.ReadLine();
+			//var p = Polynomial.Parse(s);
+			//var e = new PolynomialEquation(p, Double.Parse(eps));
+			//e.Solve();
+			////System.Console.WriteLine(String.Join(" ", e.AllRoots));
+			//System.Console.WriteLine("   Roots: " + String.Join(" ", e.Roots));
+			//System.Console.ReadKey();
 
 			//var s = System.Console.ReadLine();
 			//var evaluator = new CodeDomEval(s);
@@ -48,6 +51,12 @@ private static void Main(string[] args)
 			//e.Solve();
 			////System.Console.WriteLine(String.Join(" ", e.AllRoots));
 			//System.Console.WriteLine("   Roots: " + String.Join(" ", e.Roots));
+
+			//var f = new CodeDomEval("pow(x, 3) - 2 * pow(x, 2) - x + 2");
+			//var f = new CodeDomEval("sin(x)");
+			var e = new FunctionEquation(Math.Sin, new Interval(-5, 5), eps: 1e-15);
+			e.Solve();
+			var r = e.AllRoots;
 		}
 	}
 }
diff --git a/MyExpression.Core.Tests/CodeDomEvalTests.cs b/MyExpression.Core.Tests/CodeDomEvalTests.cs
index 9ff8087..b51c64f 100644
--- a/MyExpression.Core.Tests/CodeDomEvalTests.cs
+++ b/MyExpression.Core.Tests/CodeDomEvalTests.cs
@@ -1,10 +1,13 @@
-using NUnit.Framework;
+// Copyright (c) 2018 Vladislav Prekel
+
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
+using NUnit.Framework;
+
 namespace MyExpression.Core.Tests
 {
 	[TestFixture]
@@ -13,15 +16,12 @@ public class CodeDomEvalTests
 		[Test]
 		public void RandomSinCos()
 		{
-			Func<double, double> evalsin = new CodeDomEval("Math.Sin(x)").Calculate;
-			double sin(double x) => Math.Sin(x);
-			Func<double, double> evalcos = new CodeDomEval("Math.Cos(x)").Calculate;
+			Func<double, double> evalcos = new CodeDomEval("cos(x)").Calculate;
 			double cos(double x) => Math.Cos(x);
 			var r = new MyRandom();
-			for (var i = 0; i < 100; i++)
+			for (var i = 0; i < 10; i++)
 			{
 				var x = r.Next(100) * r.NextDouble();
-				Assert.AreEqual(sin(x), evalsin(x));
 				Assert.AreEqual(cos(x), evalcos(x));
 			}
 		}
@@ -29,14 +29,26 @@ public void RandomSinCos()
 		[Test]
 		public void Random()
 		{
-			Func<double, double> f1 = new CodeDomEval("Math.Sin(x)*1/x*4383+2143/1414+141-1.2*23*x*Math.Abs(x*Math.Sin(x))").Calculate;
+			Func<double, double> f1 = new CodeDomEval("sin(x)*1/x*4383+2143/1414+141-1.2*23*x*Math.Abs(x*Math.Sin(x))").Calculate;
 			double f(double x) => Math.Sin(x) * 1 / x * 4383 + 2143 / 1414 + 141 - 1.2 * 23 * x * Math.Abs(x * Math.Sin(x));
 			var r = new MyRandom();
-			for (var i = 0; i < 1000; i++)
+			for (var i = 0; i < 100; i++)
 			{
 				var x = r.Next(100) * r.NextDouble();
 				Assert.AreEqual(f(x), f1(x), 1e-8);
 			}
 		}
+
+		[Test]
+		public void ReadmeTest()
+		{
+			var s = "sin(x)";
+			var c = new CodeDomEval(s);
+			Func<double, double> f = c.Calculate;
+			Assert.AreEqual(0, f(0), 1e-7);
+			Assert.AreEqual(1, f(Math.PI / 2), 1e-7);
+			Assert.AreEqual(0, f(Math.PI), 1e-7);
+			Assert.AreEqual(Math.Sqrt(2) / 2, f(Math.PI / 4), 1e-7);
+		}
 	}
 }
diff --git a/MyExpression.Core.Tests/FunctionEquationTests.cs b/MyExpression.Core.Tests/FunctionEquationTests.cs
new file mode 100644
index 0000000..eb372c2
--- /dev/null
+++ b/MyExpression.Core.Tests/FunctionEquationTests.cs
@@ -0,0 +1,23 @@
+// Copyright (c) 2018 Vladislav Prekel
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+using NUnit.Framework;
+
+namespace MyExpression.Core.Tests
+{
+	[TestFixture]
+	public class FunctionEquationTests
+	{
+		[Test]
+		public void CustomTest()
+		{
+			var e1 = new FunctionEquation((x) => Math.Sin(x) * Math.Sin(x) * Math.Cos(x) / Math.Tan(x), new Interval(-5, 5), 1e-3, 1e-5);
+			e1.Solve();
+		}
+	}
+}
diff --git a/MyExpression.Core.Tests/LinearEquationTests.cs b/MyExpression.Core.Tests/LinearEquationTests.cs
index ac42911..c3b2bc4 100644
--- a/MyExpression.Core.Tests/LinearEquationTests.cs
+++ b/MyExpression.Core.Tests/LinearEquationTests.cs
@@ -43,5 +43,30 @@ public void ParseTest_Random()
 			Assert.AreEqual(a, le.A);
 			Assert.AreEqual(b, le.B);
 		}
+
+		[Test]
+		public void ToStringTest()
+		{
+			var l = new LinearEquation(1, 1);
+			Assert.AreEqual("x+1", l.ToString());
+			l = new LinearEquation(0, 1);
+			Assert.AreEqual("1", l.ToString());
+			l = new LinearEquation(1, 0);
+			Assert.AreEqual("x", l.ToString());
+			l = new LinearEquation(-1, 0);
+			Assert.AreEqual("-x", l.ToString());
+			l = new LinearEquation(-1, -1);
+			Assert.AreEqual("-x-1", l.ToString());
+			l = new LinearEquation(2, 2);
+			Assert.AreEqual("2x+2", l.ToString());
+			l = new LinearEquation(0, 2);
+			Assert.AreEqual("2", l.ToString());
+			l = new LinearEquation(2, 0);
+			Assert.AreEqual("2x", l.ToString());
+			l = new LinearEquation(-2, 0);
+			Assert.AreEqual("-2x", l.ToString());
+			l = new LinearEquation(-2, -2);
+			Assert.AreEqual("-2x-2", l.ToString());
+		}
 	}
 }
\ No newline at end of file
diff --git a/MyExpression.Core.Tests/MyExpression.Core.Tests.csproj b/MyExpression.Core.Tests/MyExpression.Core.Tests.csproj
index ed4200c..689c430 100644
--- a/MyExpression.Core.Tests/MyExpression.Core.Tests.csproj
+++ b/MyExpression.Core.Tests/MyExpression.Core.Tests.csproj
@@ -48,6 +48,7 @@
   <ItemGroup>
     <Compile Include="AssemblyInfo.cs" />
     <Compile Include="CodeDomEvalTests.cs" />
+    <Compile Include="FunctionEquationTests.cs" />
     <Compile Include="IntervalTests.cs" />
     <Compile Include="OpenCloseIntervalTests.cs" />
     <Compile Include="MyRandom.cs" />
diff --git a/MyExpression.Core.Tests/PolynomialEquationTests.cs b/MyExpression.Core.Tests/PolynomialEquationTests.cs
index aea6d44..faa0de0 100644
--- a/MyExpression.Core.Tests/PolynomialEquationTests.cs
+++ b/MyExpression.Core.Tests/PolynomialEquationTests.cs
@@ -53,7 +53,7 @@ public void Cubic_Vieta_Dgt0_Random()
 			}
 
 			var p = new Polynomial(a, b, c, d);
-			var pe = new PolynomialEquation(p, 1e-9);
+			var pe = new PolynomialEquation(p, 1e-11);
 			pe.Solve();
 
 			Assert.AreEqual(3, pe.AllRoots.Count);
@@ -95,7 +95,7 @@ public void Cubic_Manual()
 
 			for (var i = 0; i < e.Count; i++)
 			{
-				var pe = new PolynomialEquation(new Polynomial(e[i]), 1e-9);
+				var pe = new PolynomialEquation(new Polynomial(e[i]), 1e-10);
 				pe.Solve();
 				for (var j = 0; j < pe.Roots.Count; j++)
 				{
@@ -125,7 +125,7 @@ public void Cubic_Int_Deq0_Random()
 				new Monomial(c, 1),
 				new Monomial(d, 0),
 			};
-			var pe = new PolynomialEquation(p, 1e-10);
+			var pe = new PolynomialEquation(p, 1e-11);
 			pe.Solve();
 
 			Assert.AreEqual(3, pe.AllRoots.Count);
@@ -158,7 +158,7 @@ public void Cubic_Int_Dlt0_Random()
 				new Monomial(c, 1),
 				new Monomial(d, 0),
 			};
-			var pe = new PolynomialEquation(p, 1e-9);
+			var pe = new PolynomialEquation(p, 1e-10);
 			pe.Solve();
 
 			Assert.AreEqual(1, pe.AllRoots.Count);
@@ -188,7 +188,7 @@ public void Cubic_Vieta_Dlt0_Random()
 				new Monomial(c, 1),
 				new Monomial(d, 0),
 			};
-			var pe = new PolynomialEquation(p, 1e-8);
+			var pe = new PolynomialEquation(p, 1e-9);
 			pe.Solve();
 
 			Assert.AreEqual(1, pe.AllRoots.Count);
@@ -197,40 +197,6 @@ public void Cubic_Vieta_Dlt0_Random()
 			Assert.AreEqual(0, p.Calculate(pe.Roots[0]), 1e-6);
 		}
 
-		//[Test]
-		//public void Cubic_Deq0_Random()
-		//{
-		//	var r = new MyRandom();
-		//	double a, b, c, d;
-		//	while (true)
-		//	{
-		//		//a = 2 * r.NextDouble() * r.NextSign();
-		//		a = 5 * r.NextDouble() * r.NextSign();
-		//		b = 5 * r.NextDouble() * r.NextSign();
-		//		c = 5 * r.NextDouble() * r.NextSign();
-		//		d = 5 * r.NextDouble() * r.NextSign();
-		//		if (Math.Abs(CubicDiscriminant(a, b, c, d)) < 1e-7 && Math.Abs(a) >= 1e-2) break;
-		//	}
-
-		//	var p = new Polynomial
-		//	{
-		//		new Monomial(a, 3),
-		//		new Monomial(b, 2),
-		//		new Monomial(c, 1),
-		//		new Monomial(d, 0),
-		//	};
-		//	var pe = new PolynomialEquation(p, 1e-9);
-		//	pe.Solve();
-
-		//	Assert.AreEqual(3, pe.AllRoots.Count);
-		//	Assert.IsTrue(new Interval(1, 2).IsInInterval(pe.Roots.Count), pe.Roots.Count.ToString());
-
-		//	foreach (var i in pe.AllRoots)
-		//	{
-		//		Assert.AreEqual(0, p.Calculate(i), 1e-5);
-		//	}
-		//}
-
 		[Test]
 		public void Cubic_Vieta_RootsToCoef_Random()
 		{
@@ -252,7 +218,7 @@ public void Cubic_Vieta_RootsToCoef_Random()
 			c = CubicVietaC(a, x);
 			d = CubicVietaD(a, x);
 			Assert.Greater(CubicDiscriminant(a, b, c, d), 0);
-			pe = new PolynomialEquation(new Polynomial(a, b, c, d), 1e-7);
+			pe = new PolynomialEquation(new Polynomial(a, b, c, d), 1e-9);
 			pe.Solve();
 			Assert.AreEqual(3, pe.AllRoots.Count);
 			Assert.AreEqual(3, pe.Roots.Count);
@@ -280,7 +246,7 @@ public void Cubic_Vieta_RootsToCoef_Random()
 				c = CubicVietaC(a, z);
 				d = CubicVietaD(a, z);
 				Assert.AreEqual(0, CubicDiscriminant(a, b, c, d));
-				pe = new PolynomialEquation(new Polynomial(a, b, c, d), 1e-6);
+				pe = new PolynomialEquation(new Polynomial(a, b, c, d), 1e-8);
 				pe.Solve();
 				Assert.AreEqual(3, pe.AllRoots.Count);
 				Assert.IsTrue(new Interval(1, 2).IsInInterval(pe.Roots.Count), pe.Roots.Count.ToString());
@@ -289,5 +255,21 @@ public void Cubic_Vieta_RootsToCoef_Random()
 				Assert.AreEqual(z[2], pe.AllRoots[2], 1e-5);
 			}
 		}
+
+		[Test]
+		public void ReadmeTest()
+		{
+			var s = "x^3-2x^2-x+2";
+			var eps = 1e-8;
+			var p = Polynomial.Parse(s);
+			var e = new PolynomialEquation(p, eps);
+			e.Solve();
+			Assert.AreEqual(-1, e.Roots[0], 1e-7);
+			Assert.AreEqual(0, p.Calculate(e.Roots[0]), 1e-7);
+			Assert.AreEqual(1, e.Roots[1], 1e-7);
+			Assert.AreEqual(0, p.Calculate(e.Roots[1]), 1e-7);
+			Assert.AreEqual(2, e.Roots[2], 1e-7);
+			Assert.AreEqual(0, p.Calculate(e.Roots[2]), 1e-7);
+		}
 	}
 }
diff --git a/MyExpression.Core/CodeDomEval.cs b/MyExpression.Core/CodeDomEval.cs
index a66aafe..8760b69 100644
--- a/MyExpression.Core/CodeDomEval.cs
+++ b/MyExpression.Core/CodeDomEval.cs
@@ -35,6 +35,41 @@ public double Evaluate(double x)
 		}
 	}
 }";
+		private string ReformExpression(string e)
+		{
+			var sb = new StringBuilder(e);
+			sb.Replace(" ", "");
+			sb.Replace("abs", "Math.Abs");
+			sb.Replace("acos", "Math.Acos");
+			sb.Replace("asin", "Math.Asin");
+			sb.Replace("atan", "Math.Atan");
+			sb.Replace("atan2", "Math.Atan2");
+			sb.Replace("bigmul", "Math.BigMul");
+			sb.Replace("ceiling", "Math.Ceiling");
+			sb.Replace("cos", "Math.Cos");
+			sb.Replace("cosh", "Math.Cosh");
+			sb.Replace("divrem", "Math.DivRem");
+			sb.Replace("e", "Math.E");
+			sb.Replace("exp", "Math.Exp");
+			sb.Replace("floor", "Math.Floor");
+			sb.Replace("ieeeremainder", "Math.IEEERemainder");
+			sb.Replace("log", "Math.Log");
+			sb.Replace("log10", "Math.Log10");
+			sb.Replace("max", "Math.Max");
+			sb.Replace("min", "Math.Min");
+			sb.Replace("pi", "Math.PI");
+			sb.Replace("pow", "Math.Pow");
+			sb.Replace("round", "Math.Round");
+			sb.Replace("sign", "Math.Sign");
+			sb.Replace("sin", "Math.Sin");
+			sb.Replace("sinh", "Math.Sinh");
+			sb.Replace("sqrt", "Math.Sqrt");
+			sb.Replace("tan", "Math.Tan");
+			sb.Replace("tanh", "Math.Tanh");
+			sb.Replace("truncate", "Math.Truncate");
+			return sb.ToString();
+		}
+	
 		/// <summary>
 		/// Конструктор
 		/// </summary>
@@ -49,7 +84,8 @@ public CodeDomEval(string expression)
 			// Компиляция сборки с вычисляющим классом
 			var compilerParams = CreateCompilerParameters();
 			//var src = String.Format(SourceFormat, expression);
-			var src = SourceFormat.Replace("[|<expression>|]", expression);
+			var rfex = ReformExpression(expression);
+			var src = SourceFormat.Replace("[|<expression>|]", rfex);
 			CompilerResults = provider.CompileAssemblyFromSource(compilerParams, src);
 
 			if (CompilerResults.Errors.Count == 0)
@@ -62,9 +98,9 @@ public CodeDomEval(string expression)
 				// Сбор ошибок компиляции
 				foreach (CompilerError error in CompilerResults.Errors)
 				{
-					sb.Append(error.ErrorText + "\n");
+					sb.Append(error + "\n");
 				}
-				throw new Exception("Ошибка сборки\n" + sb);
+				throw new ApplicationException("Ошибка сборки\n" + sb);
 			}
 
 			if (!IsSuccessfulBuild) throw new Exception("Ошибка сборки");
diff --git a/MyExpression.Core/FunctionEquation.cs b/MyExpression.Core/FunctionEquation.cs
new file mode 100644
index 0000000..b1b2777
--- /dev/null
+++ b/MyExpression.Core/FunctionEquation.cs
@@ -0,0 +1,70 @@
+// Copyright (c) 2018 Vladislav Prekel
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MyExpression.Core
+{
+	public class FunctionEquation : IEquation
+	{
+		public Func<double, double> Function { get; private set; }
+
+		public Interval Interval { get; private set; }
+		public double Step { get; private set; }
+		public double Epsilon { get; private set; }
+
+		public FunctionEquation(Func<double, double> function, Interval interval, double step = 1e-3, double eps = 1e-8)
+		{
+			Function = function;
+			Interval = interval;
+			Step = step;
+			Epsilon = eps;
+		}
+
+		public FunctionEquation(IFunctionX functionx, Interval interval, double step = 1e-3, double eps = 1e-8)
+			: this(functionx.Calculate, interval, step, eps) { }
+
+		public IList<double> AllRoots { get; private set; }
+
+		public IList<double> Roots => AllRoots;
+
+		public void Solve()
+		{
+			AllRoots = new List<double>();
+			var x0 = Interval.Left;
+			var y0 = Function(x0);
+			var y = 0d;
+			var fl = false;
+			var x1 = Double.NaN;
+			for (var x = Interval.Left + Step; x <= Interval.Right; x += Step)
+			{
+				y = Function(x);
+
+				if (!fl && Math.Abs(y) < Epsilon)
+				{
+					fl = true;
+					x1 = x;
+				}
+				if (fl && Math.Abs(y) >= Epsilon)
+				{
+					fl = false;
+					AllRoots.Add(x1);
+				}
+
+				var p = y0 * y;
+				if (!Double.IsInfinity(p) && !Double.IsNaN(p) && p < 0)
+				{
+					var bs = new RecursiveBinarySearch(Function, new Interval(x0, x), Epsilon);
+					x1 = bs.Solve();
+					if (!fl) AllRoots.Add(x1);
+				}
+
+				y0 = y;
+				x0 = x;
+			}
+		}
+	}
+}
diff --git a/MyExpression.Core/IDerivativable.cs b/MyExpression.Core/IDerivativable.cs
new file mode 100644
index 0000000..1d535d9
--- /dev/null
+++ b/MyExpression.Core/IDerivativable.cs
@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MyExpression.Core
+{
+	public interface IDerivativable
+	{
+		IFunctionX Derivative { get; }
+		//double Calculate(double x);
+	}
+}
diff --git a/MyExpression.Core/Equation.cs b/MyExpression.Core/IEquation.cs
similarity index 85%
rename from MyExpression.Core/Equation.cs
rename to MyExpression.Core/IEquation.cs
index 1379f94..3b205d9 100644
--- a/MyExpression.Core/Equation.cs
+++ b/MyExpression.Core/IEquation.cs
@@ -8,9 +8,10 @@
 
 namespace MyExpression.Core
 {
-	interface IEquation
+	public interface IEquation
 	{
 		IList<double> AllRoots { get; }
 		IList<double> Roots { get; }
+		void Solve();
 	}
 }
diff --git a/MyExpression.Core/LinearEquation.cs b/MyExpression.Core/LinearEquation.cs
index faa6cd3..a4bae3a 100644
--- a/MyExpression.Core/LinearEquation.cs
+++ b/MyExpression.Core/LinearEquation.cs
@@ -49,7 +49,20 @@ public static LinearEquation Parse(string s)
 
 		public override string ToString()
 		{
-			return ToPolynomial() + " = 0";
+			var k = A.ToString();
+			var m = B.ToString();
+			var x = "x";
+			if (A == 0) return m;
+			if (A == 1) k = "";
+			if (A == -1) k = "-";
+			if (B > 0) m = "+" + m;
+			if (B == 0) m = "";
+			return $"{k}{x}{m}";
+		}
+
+		public void Solve()
+		{
+			
 		}
 	}
 }
diff --git a/MyExpression.Core/Monomial.cs b/MyExpression.Core/Monomial.cs
index f71a242..c210770 100644
--- a/MyExpression.Core/Monomial.cs
+++ b/MyExpression.Core/Monomial.cs
@@ -7,7 +7,7 @@
 
 namespace MyExpression.Core
 {
-	public class Monomial : IFunctionX, IComparable
+	public class Monomial : IFunctionX, IDerivativable, IComparable
 	{
 		public double Coefficient { get; set; }
 		public double Degree { get; set; }
@@ -77,7 +77,7 @@ public Monomial(double coef = 1, double degree = 1)
 			Degree = degree;
 		}
 
-		public Monomial Derivative
+		public IFunctionX Derivative
 		{
 			get
 			{
diff --git a/MyExpression.Core/MyExpression.Core.csproj b/MyExpression.Core/MyExpression.Core.csproj
index ce40839..20d6c6c 100644
--- a/MyExpression.Core/MyExpression.Core.csproj
+++ b/MyExpression.Core/MyExpression.Core.csproj
@@ -42,11 +42,15 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="Equation.cs" />
+    <Compile Include="FunctionEquation.cs" />
+    <Compile Include="IEquation.cs" />
     <Compile Include="CodeDomEval.cs" />
     <Compile Include="IBinarySearch.cs" />
+    <Compile Include="IDerivativable.cs" />
     <Compile Include="IFunctionX.cs" />
     <Compile Include="Interval.cs" />
+    <Compile Include="QuadraticParabola.cs" />
+    <Compile Include="Straight.cs" />
     <Compile Include="LinearEquation.cs" />
     <Compile Include="Monomial.cs" />
     <Compile Include="MonotonyInterval.cs" />
@@ -57,6 +61,7 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="RecursiveBinarySearch.cs" />
     <Compile Include="SquareEquation.cs" />
+    <Compile Include="Tangent.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
diff --git a/MyExpression.Core/Polynomial.cs b/MyExpression.Core/Polynomial.cs
index b458ddb..aca5359 100644
--- a/MyExpression.Core/Polynomial.cs
+++ b/MyExpression.Core/Polynomial.cs
@@ -8,7 +8,7 @@
 
 namespace MyExpression.Core
 {
-	public class Polynomial : IFunctionX, IEnumerable<Monomial>
+	public class Polynomial : IFunctionX, IDerivativable, IEnumerable<Monomial>
 	{
 		private SortedDictionary<double, Monomial> Data { get; set; } = new SortedDictionary<double, Monomial>();
 
@@ -159,14 +159,14 @@ public void Sub(Monomial a)
 			}
 		}
 
-		public Polynomial Derivative
+		public IFunctionX Derivative
 		{
 			get
 			{
 				var d = new Polynomial();
 				foreach (var i in Data.Values)
 				{
-					d.Add(i.Derivative);
+					d.Add((Monomial)i.Derivative);
 				}
 				return d;
 			}
diff --git a/MyExpression.Core/PolynomialEquation.cs b/MyExpression.Core/PolynomialEquation.cs
index 1f26fba..d19d1a5 100644
--- a/MyExpression.Core/PolynomialEquation.cs
+++ b/MyExpression.Core/PolynomialEquation.cs
@@ -13,7 +13,7 @@ public class PolynomialEquation : IEquation
 		public double Epsilon { get; set; }
 		public Polynomial Polynomial { get; private set; }
 
-		public Polynomial Derivative => Polynomial.Derivative;
+		public Polynomial Derivative => (Polynomial)Polynomial.Derivative;
 
 		private PolynomialEquation polynomialEquation;
 		public PolynomialEquation DerivativeEquation
@@ -28,7 +28,7 @@ public PolynomialEquation DerivativeEquation
 			}
 		}
 
-		public PolynomialEquation(Polynomial p, double eps = 0.00001)
+		public PolynomialEquation(Polynomial p, double eps = 1e-15)
 		{
 			Polynomial = p;
 			Epsilon = eps;
diff --git a/MyExpression.Core/QuadraticParabola.cs b/MyExpression.Core/QuadraticParabola.cs
new file mode 100644
index 0000000..2d87ff6
--- /dev/null
+++ b/MyExpression.Core/QuadraticParabola.cs
@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MyExpression.Core
+{
+	public class QuadraticParabola : SquareEquation, IFunctionX, IDerivativable
+	{
+		public QuadraticParabola(double a, double b, double c) : base(a, b, c) { }
+
+		public IFunctionX Derivative => new Straight(2 * A, B);
+
+		public double Calculate(double x) => A * x * x + B * x + C;
+	}
+}
diff --git a/MyExpression.Core/SquareEquation.cs b/MyExpression.Core/SquareEquation.cs
index 3f3c5cc..2000e1d 100644
--- a/MyExpression.Core/SquareEquation.cs
+++ b/MyExpression.Core/SquareEquation.cs
@@ -85,7 +85,28 @@ public Polynomial ToPolynomial()
 
 		public override string ToString()
 		{
-			return $"{A}x^2{(B >= 0 ? "+" + B : B.ToString())}{(C >= 0 ? "+" + C : C.ToString())} = 0";
+			var a = A.ToString();
+			var b = B.ToString();
+			var c = C.ToString();
+			if (A == 0) return new Straight(B, C).ToString();
+			var x2 = "x^2";
+			var x = "x";
+			if (A == 1) a = "";
+			if (A == -1) a = "-";
+			if (B == 0) b = x = "";
+			if (B == 1) b = "";
+			if (B > 0) b = "+" + b;
+			if (B == -1) b = "-";
+			if (B == 1) b = "";
+			if (B == -1) b = "-";
+			if (C == 0) c = "";
+			if (C > 0) c = "+" + c;
+			return $"{a}{x2}{b}{x}{c}";
+		}
+
+		public void Solve()
+		{
+			
 		}
 	}
 }
diff --git a/MyExpression.Core/Straight.cs b/MyExpression.Core/Straight.cs
new file mode 100644
index 0000000..a75ea54
--- /dev/null
+++ b/MyExpression.Core/Straight.cs
@@ -0,0 +1,23 @@
+// Copyright (c) 2018 Vladislav Prekel
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MyExpression.Core
+{
+	public class Straight : LinearEquation, IFunctionX, IDerivativable
+	{
+		public IFunctionX Derivative => new Straight(0, A);
+
+		public Straight() : base(0, 0) { }
+
+		public Straight(double k, double m) : base(k, m) { }
+
+		public Straight(PolynomialEquation p) : base(p) { }
+
+		public double Calculate(double x) => A * x + B;
+	}
+}
diff --git a/MyExpression.Core/Tangent.cs b/MyExpression.Core/Tangent.cs
new file mode 100644
index 0000000..5ef7f3e
--- /dev/null
+++ b/MyExpression.Core/Tangent.cs
@@ -0,0 +1,36 @@
+// Copyright (c) 2018 Vladislav Prekel
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MyExpression.Core
+{
+	public class Tangent : Straight
+	{
+		public Tangent(IFunctionX function, double x0, double lim)
+		{
+			double k, m;
+			if (function is IDerivativable p)
+			{
+				var d = p.Derivative;
+				k = d.Calculate(x0);
+				m = function.Calculate(x0) - d.Calculate(x0) * x0;
+			}
+			else
+			{
+				var fn = function;
+				var x1 = x0 + lim;
+				var y0 = fn.Calculate(x0);
+				var y1 = fn.Calculate(x1);
+
+				k = (y1 - y0) / (x1 - x0);
+				m = y0 - k * x0;
+			}
+			A = k;
+			B = m;
+		}
+	}
+}
diff --git a/MyExpression.Wpf/BrushesList.cs b/MyExpression.Wpf/BrushesList.cs
index 7f0b6ec..c8c54c8 100644
--- a/MyExpression.Wpf/BrushesList.cs
+++ b/MyExpression.Wpf/BrushesList.cs
@@ -33,39 +33,66 @@ static BrushesList()
 			}
 		}
 
-		public SolidColorBrush SelectedBrush => ((SolidColorBrush)((Rectangle)(((Grid)SelectedItem).Children[0])).Fill);
+		//public SolidColorBrush SelectedBrush => ((SolidColorBrush)((Rectangle)(((Grid)SelectedItem).Children[0])).Fill);
+		public SolidColorBrush SelectedBrush
+		{
+			get => ((BrushGrid)SelectedItem).Brush;
+			set
+			{
+				var c = 0;
+				var dm = 0;
+				foreach (var i in Brushes)
+				{
+					if (i.Item2.Equals(value))
+					{
+						dm = c;
+					}
+					c++;
+				}
+				SelectedIndex = dm;
+			}
+		}
 
-		public BrushesList() : base()
+		public class BrushGrid : Grid
 		{
-			var c = 0;
-			var dm = 0;
-			foreach (var i in Brushes)
+			public SolidColorBrush Brush { get; set; }
+			public Rectangle Rectangle { get; set; }
+			public Label Label { get; set; }
+
+			public BrushGrid(string colorName, SolidColorBrush brush) : base()
 			{
-				var r = new Rectangle
+				Brush = brush;
+				Rectangle = new Rectangle
 				{
 					Width = 29,
 					Margin = new Thickness(1, 1, 0, 1),
 					HorizontalAlignment = HorizontalAlignment.Left,
-					Fill = i.Item2,
+					Fill = brush,
 					Stroke = System.Windows.Media.Brushes.Black
 				};
 
-				var l = new Label
+				Label = new Label
 				{
 					Width = Width - 30,
-					Content = i.Item1,
+					Content = colorName,
 					Margin = new Thickness(30, -2, 0, 0),
 					HorizontalAlignment = HorizontalAlignment.Left
 				};
 
-				var g = new Grid
-				{
-					Width = Width,
-					Height = 25
-				};
-				g.Children.Add(r);
-				g.Children.Add(l);
+				Width = Width;
+				Height = 25;
+				Children.Add(Rectangle);
+				Children.Add(Label);
+			}
+		}
 
+		public BrushesList() : base()
+		{
+			var c = 0;
+			var dm = 0;
+			foreach (var i in Brushes)
+			{
+				var g = new BrushGrid(i.Item1, i.Item2);
 				Items.Add(g);
 
 				if (i.Item2.Equals(System.Windows.Media.Brushes.DarkMagenta))
@@ -74,7 +101,7 @@ public BrushesList() : base()
 				}
 				c++;
 			}
-			SelectedIndex = dm;
+			//SelectedIndex = dm;
 		}
 	}
 }
diff --git a/MyExpression.Wpf/FunctionGraph.cs b/MyExpression.Wpf/FunctionGraph.cs
index dd72c50..5b494e5 100644
--- a/MyExpression.Wpf/FunctionGraph.cs
+++ b/MyExpression.Wpf/FunctionGraph.cs
@@ -41,7 +41,7 @@ public class DrawableFunction
 			// TODO: разобраться с сеттером
 			public bool IsDrawed { get; set; }
 
-			public SolidColorBrush RootsBrush { get; private set; } = Brushes.Indigo;
+			public SolidColorBrush RootsBrush { get; set; } = Brushes.Indigo;
 
 			public IList<double> Roots { get; set; }
 
@@ -69,8 +69,21 @@ public DrawableFunction this[int index]
 
 		public void ResetTranslateTransform()
 		{
+			var dx = 0.5d;
+			var dy = 0.5d;
+			if (Parent is Panel p)
+			{
+				dx += p.ActualWidth % 1;
+				dy += p.ActualHeight % 1;
+			}
 			var tg1 = (TransformGroup)RenderTransform;
-			var tt = new TranslateTransform((int)(ActualWidth / 2 + Offset.X * Scale.X) + 0.5, -(int)(ActualHeight / 2 + Offset.Y * Scale.Y) + 0.5);
+
+			var x = ActualWidth / 2 + Offset.X * Scale.X;
+			var intx = Math.Round(x) + dx;
+			var y = ActualHeight / 2 + Offset.Y * Scale.Y;
+			var inty = -Math.Round(y) - dy;
+
+			var tt = new TranslateTransform(intx, inty);
 			if (tg1.Children.Count == 3) tg1.Children.Add(tt);
 			else tg1.Children[3] = tt;
 		}
@@ -81,15 +94,19 @@ public void DrawAxis()
 			{
 				X1 = 0,
 				X2 = 0,
-				Y1 = -ActualHeight / 2,
-				Y2 = ActualHeight / 2,
+				Y1 = -((int)(ActualHeight / 2)),
+				Y2 = (int)(ActualHeight / 2),
+				//Y1 = -((int)(ActualHeight / 2) + 0.5),
+				//Y2 = (int)(ActualHeight / 2) + 0.5,
 				Stroke = Brushes.Black,
 				StrokeThickness = 1
 			};
 			var l2 = new Line
 			{
-				X1 = -ActualWidth / 2,
-				X2 = ActualWidth / 2,
+				X1 = -((int)(ActualWidth / 2)),
+				X2 = (int)(ActualWidth / 2),
+				//X1 = -((int)(ActualWidth / 2) + 0.5),
+				//X2 = (int)(ActualWidth / 2) + 0.5,
 				Y1 = 0,
 				Y2 = 0,
 				Stroke = Brushes.Black,
@@ -117,7 +134,7 @@ public void DrawFunctions()
 						p.Y.Equals(Double.PositiveInfinity) ||
 						p.Y.Equals(Double.NegativeInfinity) ||
 						p.Y >= 1e5 ||
-						p.Y <= -1e5)
+						p.Y <= -1e5) // TODO: поменять 1e5
 					{
 						if (l.Points.Count > 0)
 						{
diff --git a/MyExpression.Wpf/FunctionsListView.cs b/MyExpression.Wpf/FunctionsListView.cs
new file mode 100644
index 0000000..0e90ad9
--- /dev/null
+++ b/MyExpression.Wpf/FunctionsListView.cs
@@ -0,0 +1,82 @@
+// Copyright (c) 2018 Vladislav Prekel
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+using MyExpression.Core;
+
+namespace MyExpression.Wpf
+{
+	public class FunctionsListView : ListView, IEnumerable<GraphableFunction>
+	{
+		public IList<GraphableFunction> Functions 
+		{
+			get => (IList<GraphableFunction>)ItemsSource;
+			set => ItemsSource = value;
+		}
+
+		public GraphableFunction SelectedFunction
+		{
+			get => (GraphableFunction)SelectedItem;
+			set => SelectedItem = value;
+		}
+
+		public FunctionsListView() : base()
+		{
+			var gv = new GridView();
+			gv.Columns.Add(new GridViewColumn() { Header = "№", DisplayMemberBinding = new Binding("Number") });
+			gv.Columns.Add(new GridViewColumn() { Header = "Формула", DisplayMemberBinding= new Binding("Formula")});
+			gv.Columns.Add(new GridViewColumn() { Header = "Тип", DisplayMemberBinding = new Binding("Type") });
+			View = gv;
+			SelectionMode = SelectionMode.Single;
+			SizeChanged += FunctionsListView_SizeChanged;
+			Loaded += FunctionsListView_Loaded;
+			MouseDoubleClick += (s, ea) => SelectedFunction = null;
+		}
+
+		public double MinFormulaColumnWidth { get; set; } = 100;
+
+		private void FunctionsListView_Loaded(object sender, RoutedEventArgs e)
+		{
+			var gv = (GridView)View;
+			var a = 0;
+			var b = 90;
+			gv.Columns[0].Width = a;
+			gv.Columns[2].Width = b;
+			gv.Columns[1].Width = Math.Max(ActualWidth - a - b - 10, MinFormulaColumnWidth);
+		}
+
+		private void FunctionsListView_SizeChanged(object sender, SizeChangedEventArgs e)
+		{
+			var gv = (GridView)View;
+			var inc = e.NewSize.Width - e.PreviousSize.Width;
+			if (gv.Columns[1].Width + inc >= MinFormulaColumnWidth || inc > 0)
+			{
+				gv.Columns[1].Width += inc;
+			}
+		}
+
+		public IEnumerator<GraphableFunction> GetEnumerator()
+		{
+			return Functions.GetEnumerator();
+		}
+
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return Functions.GetEnumerator();
+		}
+	}
+}
diff --git a/MyExpression.Wpf/GraphableFunction.cs b/MyExpression.Wpf/GraphableFunction.cs
new file mode 100644
index 0000000..1003f28
--- /dev/null
+++ b/MyExpression.Wpf/GraphableFunction.cs
@@ -0,0 +1,39 @@
+// Copyright (c) 2018 Vladislav Prekel
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+using MyExpression.Core;
+
+namespace MyExpression.Wpf
+{
+	public class GraphableFunction
+	{
+		public IFunctionX Function { get; set; }
+		public FunctionGraph.DrawableFunction GraphFunction { get; set; }
+		public string Formula { get; private set; }
+		public int Number => ParentList.IndexOf(this);
+		public string Type => Function.GetType().Name;
+		public IList<GraphableFunction> ParentList { get; set; }
+
+		public GraphableFunction(IFunctionX f, FunctionGraph.DrawableFunction gf, string formula, IList<GraphableFunction> parentList = null)
+		{
+			Function = f;
+			GraphFunction = gf;
+			Formula = formula;
+			ParentList = parentList;
+		}
+	}
+}
diff --git a/MyExpression.Wpf/Icons/16x16.png b/MyExpression.Wpf/Icons/16x16.png
new file mode 100644
index 0000000..29930f0
Binary files /dev/null and b/MyExpression.Wpf/Icons/16x16.png differ
diff --git a/MyExpression.Wpf/Icons/240x240.png b/MyExpression.Wpf/Icons/240x240.png
new file mode 100644
index 0000000..1ce2d54
Binary files /dev/null and b/MyExpression.Wpf/Icons/240x240.png differ
diff --git a/MyExpression.Wpf/Icons/32x32.png b/MyExpression.Wpf/Icons/32x32.png
new file mode 100644
index 0000000..e93b65a
Binary files /dev/null and b/MyExpression.Wpf/Icons/32x32.png differ
diff --git a/MyExpression.Wpf/Icons/48x48.png b/MyExpression.Wpf/Icons/48x48.png
new file mode 100644
index 0000000..1339398
Binary files /dev/null and b/MyExpression.Wpf/Icons/48x48.png differ
diff --git a/MyExpression.Wpf/Icons/Icon1.ico b/MyExpression.Wpf/Icons/Icon1.ico
new file mode 100644
index 0000000..8dc393d
Binary files /dev/null and b/MyExpression.Wpf/Icons/Icon1.ico differ
diff --git a/MyExpression.Wpf/Icons/Thumbs.db b/MyExpression.Wpf/Icons/Thumbs.db
new file mode 100644
index 0000000..55d407f
Binary files /dev/null and b/MyExpression.Wpf/Icons/Thumbs.db differ
diff --git a/MyExpression.Wpf/MainWindow.xaml b/MyExpression.Wpf/MainWindow.xaml
index 580904f..ade8044 100644
--- a/MyExpression.Wpf/MainWindow.xaml
+++ b/MyExpression.Wpf/MainWindow.xaml
@@ -6,51 +6,178 @@
         xmlns:local="clr-namespace:MyExpression.Wpf"
         mc:Ignorable="d"
         Title="MyExpression.Wpf" Height="500" Width="675"
-		MinHeight="425" MinWidth="425">
+		MinHeight="465" MinWidth="425">
 	<Grid>
-		<local:FunctionGraph x:Name="Graph" Margin="300,40,40,40" RenderTransformOrigin="0.5,0.5" SizeChanged="Graph_SizeChanged">
-			<local:FunctionGraph.RenderTransform>
-				<TransformGroup>
-					<ScaleTransform ScaleY="-1" ScaleX="1"/>
-					<SkewTransform AngleY="0" AngleX="0"/>
-					<RotateTransform Angle="0"/>
-				</TransformGroup>
-			</local:FunctionGraph.RenderTransform>
-		</local:FunctionGraph>
-		<Rectangle Fill="White" HorizontalAlignment="Left" Width="300"/>
-		<Rectangle Fill="White"  Height="40" VerticalAlignment="Top" Margin="0,0,0,0"/>
-		<Rectangle Fill="White"  Height="40" VerticalAlignment="Bottom" Margin="0,0,0,0"/>
-		<Rectangle Fill="White" HorizontalAlignment="Right" Width="40"/>
-		<Button x:Name="ResetButton" Content="Reset" HorizontalAlignment="Left" Margin="165,11,0,0" VerticalAlignment="Top" Width="75" Click="ResetButton_Click"/>
-		<Button x:Name="DrawButton" Content="Draw" HorizontalAlignment="Left" Margin="165,36,0,0" VerticalAlignment="Top" Width="75" Click="DrawButton_Click"/>
-		<TextBox x:Name="OffsetX" HorizontalAlignment="Left" Height="23" Margin="115,61,0,0" TextWrapping="Wrap" Text="0" VerticalAlignment="Top" Width="60"/>
-		<TextBox x:Name="OffsetY" HorizontalAlignment="Left" Height="23" Margin="180,61,0,0" TextWrapping="Wrap" Text="0" VerticalAlignment="Top" Width="60"/>
-		<Label Content="Offset" HorizontalAlignment="Left" Margin="66,61,0,0" VerticalAlignment="Top" Height="28" Width="49"/>
-		<TextBox x:Name="ScaleX" HorizontalAlignment="Left" Height="23" Margin="115,89,0,0" TextWrapping="Wrap" Text="40" VerticalAlignment="Top" Width="60"/>
-		<TextBox x:Name="ScaleY" HorizontalAlignment="Left" Height="23" Margin="180,89,0,0" TextWrapping="Wrap" Text="40" VerticalAlignment="Top" Width="60"/>
-		<Label Content="Scale" HorizontalAlignment="Left" Margin="66,89,0,0" VerticalAlignment="Top" Height="28" Width="49"/>
-		<TextBox x:Name="Step" HorizontalAlignment="Left" Height="23" Margin="115,117,0,0" TextWrapping="Wrap" Text="0,01" VerticalAlignment="Top" Width="125"/>
-		<Label Content="Step" HorizontalAlignment="Left" Margin="76,117,0,0" VerticalAlignment="Top" Height="28" Width="39"/>
-		<TextBox x:Name="CellsStepX" HorizontalAlignment="Left" Height="23" Margin="115,201,0,0" TextWrapping="Wrap" Text="1" VerticalAlignment="Top" Width="60"/>
-		<Label Content="CellsStep" HorizontalAlignment="Left" Margin="51,201,0,0" VerticalAlignment="Top" Height="28" Width="64"/>
-		<TextBox x:Name="CellsStepY" HorizontalAlignment="Left" Height="23" Margin="180,201,0,0" TextWrapping="Wrap" Text="1" VerticalAlignment="Top" Width="60"/>
-
-		<Label Content="CellsIntervalX" HorizontalAlignment="Left" Margin="29,145,0,0" VerticalAlignment="Top" Height="28"/>
-		<TextBox x:Name="CellsIntervalXLeft" HorizontalAlignment="Left" Height="23" Margin="115,145,0,0" TextWrapping="Wrap" Text="-10" VerticalAlignment="Top" Width="60"/>
-		<TextBox x:Name="CellsIntervalXRight" HorizontalAlignment="Left" Height="23" Margin="180,145,0,0" TextWrapping="Wrap" Text="10" VerticalAlignment="Top" Width="60"/>
-		<Label Content="CellsIntervalY" HorizontalAlignment="Left" Margin="29,173,0,0" VerticalAlignment="Top" Height="28"/>
-		<TextBox x:Name="CellsIntervalYLeft" HorizontalAlignment="Left" Height="23" Margin="115,173,0,0" TextWrapping="Wrap" Text="-10" VerticalAlignment="Top" Width="60"/>
-		<TextBox x:Name="CellsIntervalYRight" HorizontalAlignment="Left" Height="23" Margin="180,173,0,0" TextWrapping="Wrap" Text="10" VerticalAlignment="Top" Width="60"/>
-		<Label Content="Polynomial/Function" HorizontalAlignment="Left" Margin="-3,229,0,0" VerticalAlignment="Top" Height="28" Width="118"/>
-		<TextBox x:Name="Polynomial" HorizontalAlignment="Left" Height="45" Margin="10,257,0,0" TextWrapping="Wrap" Text="x^3-2x^2-x+2" VerticalAlignment="Top" Width="230"/>
-		<Label Content="DefinitionArea" HorizontalAlignment="Left" Margin="24,307,0,0" VerticalAlignment="Top" Height="28" Width="91"/>
-		<TextBox x:Name="DefinitionAreaLeft" HorizontalAlignment="Left" Height="23" Margin="115,307,0,0" TextWrapping="Wrap" Text="-20" VerticalAlignment="Top" Width="60"/>
-		<TextBox x:Name="DefinitionAreaRight" HorizontalAlignment="Left" Height="23" Margin="180,307,0,0" TextWrapping="Wrap" Text="20" VerticalAlignment="Top" Width="60"/>
-		<Button x:Name="AddButton" Content="Add" HorizontalAlignment="Left" Margin="115,232,0,0" VerticalAlignment="Top" Width="60" Click="AddButton_Click"/>
-		<Button x:Name="ClearButton" Content="Clear" HorizontalAlignment="Left" Margin="180,232,0,0" VerticalAlignment="Top" Width="60" Click="ClearButton_Click"/>
-		<Label Content="Count" HorizontalAlignment="Left" Margin="66,33,0,0" VerticalAlignment="Top" Height="28" Width="49"/>
-		<Label x:Name="CountLabel" Content="0" HorizontalAlignment="Left" Margin="115,33,0,0" VerticalAlignment="Top" Width="45"/>
-		<local:BrushesList x:Name="GraphBrushComboBox" Margin="10,335,0,0" Height="30" VerticalAlignment="Top" HorizontalAlignment="Left" Width="150"/>
-		<Button x:Name="SolveButton" Content="Solve" HorizontalAlignment="Left" Margin="165,335,0,0" VerticalAlignment="Top" Width="75" Click="SolveButton_Click"/>
+		<Grid.RowDefinitions>
+		</Grid.RowDefinitions>
+		<Grid.ColumnDefinitions>
+			<ColumnDefinition Width="260*" MinWidth="255"/>
+			<ColumnDefinition Width="auto"/>
+			<ColumnDefinition Width="410*" MinWidth="80"/>
+		</Grid.ColumnDefinitions>
+
+		<Grid Grid.Column="2" Grid.RowSpan="2" >
+			<local:FunctionGraph x:Name="Graph" RenderTransformOrigin="0.5,0.5" SizeChanged="Graph_SizeChanged" Loaded="Graph_Loaded">
+				<local:FunctionGraph.RenderTransform>
+					<TransformGroup>
+						<ScaleTransform ScaleY="-1" ScaleX="1"/>
+						<SkewTransform AngleY="0" AngleX="0"/>
+						<RotateTransform Angle="0"/>
+					</TransformGroup>
+				</local:FunctionGraph.RenderTransform>
+			</local:FunctionGraph>
+		</Grid>
+		<Grid>
+			<Grid.RowDefinitions>
+				<RowDefinition Height="300" MinHeight="290"/>
+				<RowDefinition Height="auto"/>
+				<RowDefinition Height="1*"/>
+			</Grid.RowDefinitions>
+			<Grid.ColumnDefinitions>
+			</Grid.ColumnDefinitions>
+			<TabControl SelectedIndex="1">
+				<TabItem Header="Плоскость">
+					<Grid>
+						<Grid.ColumnDefinitions>
+							<ColumnDefinition Width="15"/>
+							<ColumnDefinition Width="35*"/>
+							<ColumnDefinition Width="18*"/>
+							<ColumnDefinition Width="5"/>
+							<ColumnDefinition Width="18*"/>
+							<ColumnDefinition Width="15"/>
+						</Grid.ColumnDefinitions>
+						<Grid.RowDefinitions>
+							<RowDefinition Height="15"/>
+							<RowDefinition/>
+						</Grid.RowDefinitions>
+
+						<Button x:Name="ClearButton" Content="Clear" VerticalAlignment="Top" Click="ClearButton_Click" Height="20" Grid.Row="1" Grid.Column="4"/>
+
+						<Label Content="Count" Margin="0,193,5,0" VerticalAlignment="Top" Height="28" FlowDirection="RightToLeft" HorizontalAlignment="Right" Width="104" Grid.Row="1" Grid.Column="1" />
+						<Label x:Name="CountLabel" Content="0" Margin="0,193,1,0" VerticalAlignment="Top" Height="26" Grid.Row="1" Grid.Column="2" />
+
+						<Button x:Name="ResetButton" Content="Reset" VerticalAlignment="Top" Click="ResetButton_Click" Height="20" Grid.Column="2" Grid.Row="1"/>
+						<!--<Button x:Name="DrawButton" Content="Draw" Click="DrawButton_Click" Grid.Row="1" Margin="0,193,0,0" Height="20" VerticalAlignment="Top" Grid.Column="4"/>-->
+						<TextBox x:Name="OffsetX" Height="23" Margin="0,25,0,0" TextWrapping="Wrap" Text="0" VerticalAlignment="Top" Grid.Column="2" Grid.Row="1"/>
+						<TextBox x:Name="OffsetY" Height="23" Margin="0,25,0,0" TextWrapping="Wrap" Text="0" VerticalAlignment="Top" Grid.Column="4" Grid.Row="1"/>
+						<Label Content="Offset" HorizontalAlignment="Right" Margin="0,25,5,0" VerticalAlignment="Top" Height="28" Width="104" FlowDirection="RightToLeft" Grid.Row="1" Grid.Column="1"/>
+						<TextBox x:Name="ScaleX" Height="23" Margin="0,53,0,0" TextWrapping="Wrap" Text="40" VerticalAlignment="Top" Grid.Column="2" Grid.Row="1"/>
+						<TextBox x:Name="ScaleY" Height="23" Margin="0,53,0,0" TextWrapping="Wrap" Text="40" VerticalAlignment="Top" Grid.Column="4" Grid.Row="1"/>
+						<Label Content="Scale" HorizontalAlignment="Right" Margin="0,53,5,0" VerticalAlignment="Top" Height="28" Width="104" FlowDirection="RightToLeft" Grid.Row="1" Grid.Column="1"/>
+						<TextBox x:Name="Step" Height="23" Margin="0,81,0,0" TextWrapping="Wrap" Text="1e-2" VerticalAlignment="Top" Grid.Column="2" Grid.ColumnSpan="3" Grid.Row="1"/>
+						<Label Content="Step" HorizontalAlignment="Right" Margin="0,81,5,0" VerticalAlignment="Top" Height="28" Width="104" FlowDirection="RightToLeft" Grid.Row="1" Grid.Column="1"/>
+						<TextBox x:Name="CellsStepX" Height="23" Margin="0,165,0,0" TextWrapping="Wrap" Text="1" VerticalAlignment="Top" Grid.Column="2" Grid.Row="1"/>
+						<Label Content="CellsStep" HorizontalAlignment="Right" Margin="0,165,5,0" VerticalAlignment="Top" Height="28" Width="104" FlowDirection="RightToLeft" Grid.Row="1" Grid.Column="1"/>
+						<TextBox x:Name="CellsStepY" Height="23" Margin="0,165,0,0" TextWrapping="Wrap" Text="1" VerticalAlignment="Top" Grid.Column="4" Grid.Row="1"/>
+
+						<Label Content="CellsIntervalX" HorizontalAlignment="Right" Margin="0,109,5,0" VerticalAlignment="Top" Height="28" Width="104" FlowDirection="RightToLeft" Grid.Row="1" Grid.Column="1"/>
+						<TextBox x:Name="CellsIntervalXLeft" Height="23" Margin="0,109,0,0" TextWrapping="Wrap" Text="-10" VerticalAlignment="Top" Grid.Column="2" Grid.Row="1"/>
+						<TextBox x:Name="CellsIntervalXRight" Height="23" Margin="0,109,0,0" TextWrapping="Wrap" Text="10" VerticalAlignment="Top" Grid.Column="4" Grid.Row="1"/>
+						<Label Content="CellsIntervalY" HorizontalAlignment="Right" Margin="0,137,5,0" VerticalAlignment="Top" Height="28" Width="104" FlowDirection="RightToLeft" Grid.Row="1" Grid.Column="1"/>
+						<TextBox x:Name="CellsIntervalYLeft" Height="23" Margin="0,137,0,0" TextWrapping="Wrap" Text="-10" VerticalAlignment="Top" Grid.Column="2" Grid.Row="1"/>
+						<TextBox x:Name="CellsIntervalYRight" Height="23" Margin="0,137,0,0" TextWrapping="Wrap" Text="10" VerticalAlignment="Top" Grid.Column="4" Grid.Row="1"/>
+					</Grid>
+				</TabItem>
+				<TabItem Header="Добавление">
+					<Grid>
+						<Grid.ColumnDefinitions>
+							<ColumnDefinition Width="15"/>
+							<ColumnDefinition Width="60*"/>
+							<ColumnDefinition Width="55*"/>
+							<ColumnDefinition Width="5"/>
+							<ColumnDefinition Width="55*"/>
+							<ColumnDefinition Width="5"/>
+							<ColumnDefinition Width="55*"/>
+							<ColumnDefinition Width="15"/>
+						</Grid.ColumnDefinitions>
+						<Grid.RowDefinitions>
+							<RowDefinition Height="15"/>
+							<RowDefinition/>
+						</Grid.RowDefinitions>
+						<Label Content="Type" VerticalAlignment="Top" Height="28" FlowDirection="RightToLeft" Grid.Row="1" Grid.Column="1" Grid.ColumnSpan="2" Margin="0,0,22,0"/>
+						<TextBox x:Name="Polynomial" Height="38" TextWrapping="Wrap" Text="x^3-2x^2-x+2" VerticalAlignment="Top" Margin="0,28,0,0" Grid.Row="1" Grid.Column="1" Grid.ColumnSpan="6"/>
+						<TextBox x:Name="DefinitionAreaLeft" Height="23" TextWrapping="Wrap" Text="-20" VerticalAlignment="Top" Margin="0,98,0,0" Grid.Row="1" Grid.Column="4"/>
+						<TextBox x:Name="DefinitionAreaRight" Height="23" TextWrapping="Wrap" Text="20" VerticalAlignment="Top" Margin="0,98,0,0" Grid.Row="1" Grid.Column="6"/>
+						<Button x:Name="AddButton" Content="Add" VerticalAlignment="Top" Click="AddButton_Click" Height="20" Margin="0,126,1,0" Grid.Row="1" Grid.Column="6"/>
+						<local:BrushesList x:Name="GraphBrushComboBox" Margin="0,126,0,0" HorizontalAlignment="Right" Grid.Row="1" Grid.ColumnSpan="4" Grid.Column="1" Height="30" VerticalAlignment="Top" Width="150" SelectedBrush="DarkMagenta"/>
+						<Label Content="DefinitionArea" HorizontalAlignment="Right" Margin="0,98,0,0" VerticalAlignment="Top" Height="28" Width="100" Grid.Row="1" Grid.Column="1" FlowDirection="RightToLeft" Grid.ColumnSpan="2"/>
+						<ComboBox x:Name="TypeComboBox" Grid.ColumnSpan="5" Grid.Column="2" Margin="35,0,0,0" Grid.Row="1" VerticalAlignment="Top" Height="25" SelectedIndex="0" SelectionChanged="ComboBox_SelectionChanged">
+							<ComboBoxItem Content="Auto"/>
+							<ComboBoxItem Content="Polynomial" />
+							<ComboBoxItem Content="CodeDomEval"/>
+							<ComboBoxItem Content="Straight"/>
+							<ComboBoxItem Content="QuadraticParabola"/>
+						</ComboBox>
+
+						<Label Content="A/B/C" HorizontalAlignment="Right" Margin="0,70,5,0" VerticalAlignment="Top" Height="28" Width="50" Grid.Row="1" Grid.Column="1" FlowDirection="RightToLeft"/>
+						<TextBox x:Name="ABox" Height="23" TextWrapping="Wrap" Text="1" VerticalAlignment="Top" Margin="0,71,0,0" Grid.Row="1" Grid.Column="2" IsEnabled="False"/>
+						<TextBox x:Name="BBox" Height="23" TextWrapping="Wrap" Text="-2" VerticalAlignment="Top" Margin="0,70,0,0" Grid.Row="1" Grid.Column="4" IsEnabled="False"/>
+						<TextBox x:Name="CBox" Height="23" TextWrapping="Wrap" Text="0" VerticalAlignment="Top" Margin="0,70,0,0" Grid.Row="1" Grid.Column="6" IsEnabled="False"/>
+					</Grid>
+				</TabItem>
+				<TabItem Header="Касательная">
+					<Grid>
+						<Grid.ColumnDefinitions>
+							<ColumnDefinition Width="15"/>
+							<ColumnDefinition Width="35*"/>
+							<ColumnDefinition Width="18*"/>
+							<ColumnDefinition Width="5"/>
+							<ColumnDefinition Width="18*"/>
+							<ColumnDefinition Width="15"/>
+						</Grid.ColumnDefinitions>
+						<Grid.RowDefinitions>
+							<RowDefinition Height="15"/>
+							<RowDefinition Height="105"/>
+							<RowDefinition/>
+						</Grid.RowDefinitions>
+
+						<Button x:Name="TangentAddButton" Content="Add" Margin="0,56,0,0" VerticalAlignment="Top" Click="TangentAddButton_Click" Height="20" Grid.Row="1" Grid.Column="4" IsEnabled="False" />
+
+						<Label Content="TangentLim" Margin="0,28,0,0" VerticalAlignment="Top" Height="28" HorizontalAlignment="Right" Width="105" Grid.Row="1"  FlowDirection="RightToLeft" Grid.Column="1"/>
+						<TextBox x:Name="TangentLim" Height="23" Margin="0,28,0,0" TextWrapping="Wrap" Text="1e-8" VerticalAlignment="Top" Grid.Row="1" Grid.Column="2"/>
+
+						<Label Content="TangentX" Margin="0,0,0,0" VerticalAlignment="Top" Height="28" HorizontalAlignment="Right" Width="105" Grid.Row="1" FlowDirection="RightToLeft" Grid.Column="1" />
+						<TextBox x:Name="TangentX" Height="23" TextWrapping="Wrap" Text="0" VerticalAlignment="Top" Grid.Row="1" Grid.Column="2"/>
+
+						<local:BrushesList x:Name="TangentBrushComboBox" Margin="0,56,1,0" Grid.Row="1" Grid.ColumnSpan="2" Grid.Column="1" HorizontalAlignment="Right" Width="150" SelectedBrush="DarkOrange" Height="30" VerticalAlignment="Top"/>
+					</Grid>
+				</TabItem>
+				<TabItem Header="Решение">
+					<Grid>
+						<Grid.ColumnDefinitions>
+							<ColumnDefinition Width="15"/>
+							<ColumnDefinition Width="35*"/>
+							<ColumnDefinition Width="18*"/>
+							<ColumnDefinition Width="5"/>
+							<ColumnDefinition Width="18*"/>
+							<ColumnDefinition Width="15"/>
+						</Grid.ColumnDefinitions>
+						<Grid.RowDefinitions>
+							<RowDefinition Height="15"/>
+							<RowDefinition Height="134"/>
+							<RowDefinition/>
+						</Grid.RowDefinitions>
+						<Button x:Name="SolveButton" Content="Solve" Margin="0,104,0,0" VerticalAlignment="Top" Click="SolveButton_Click" Height="20" Grid.Row="1" Grid.Column="4" IsEnabled="False" />
+						<Button x:Name="EraseButton" Content="Erase" Margin="0,85,0,0" VerticalAlignment="Top" Click="EraseButton_Click"  Height="0" Grid.Row="1" Grid.Column="4" />
+						<CheckBox x:Name="MultipleRootsCheckBox" Content="Multiple roots" Margin="0,84,40,0" Grid.Row="1" VerticalAlignment="Top" FlowDirection="RightToLeft" Grid.Column="1" IsChecked="True" Height="15" Grid.ColumnSpan="2"/>
+						<TextBox x:Name="SolveEpsilon" Height="23" Grid.Row="1" TextWrapping="Wrap" Text="1e-15" VerticalAlignment="Top" Grid.Column="2"/>
+						<Label Content="Epsilon" HorizontalAlignment="Right" Grid.Row="1" VerticalAlignment="Top" Width="105" FlowDirection="RightToLeft" Grid.Column="1" Height="26"/>
+						<TextBox x:Name="RootsTextBox" TextWrapping="Wrap" Grid.ColumnSpan="4" Margin="0,10" Grid.Row="2" Grid.Column="1" />
+						<local:BrushesList x:Name="RootsBrushComboBox" HorizontalAlignment="Right" Grid.Row="1" Grid.ColumnSpan="2" Height="30" VerticalAlignment="Top" Width="150" SelectedBrush="Indigo" Grid.Column="1" Margin="0,104,0,0"/>
+						<TextBox x:Name="SolveStep" Height="23" Grid.Row="1" TextWrapping="Wrap" Text="1e-3" VerticalAlignment="Top" Grid.Column="2" Margin="0,28,0,0"/>
+						<Label Content="Step" HorizontalAlignment="Right" Grid.Row="1" VerticalAlignment="Top" Width="105" FlowDirection="RightToLeft" Grid.Column="1" Height="26" Margin="0,28,0,0"/>
+						<TextBox x:Name="SolveIntervalLeft" Height="23" Grid.Row="1" TextWrapping="Wrap" Text="-5" VerticalAlignment="Top" Grid.Column="2" Margin="0,56,0,0"/>
+						<Label Content="Interval" HorizontalAlignment="Right" Grid.Row="1" VerticalAlignment="Top" Width="105" FlowDirection="RightToLeft" Grid.Column="1" Height="26" Margin="0,56,0,0"/>
+						<TextBox x:Name="SolveIntervalRight" Height="23" Grid.Row="1" TextWrapping="Wrap" Text="5" VerticalAlignment="Top" Grid.Column="4" Margin="0,56,0,0"/>
+					</Grid>
+				</TabItem>
+			</TabControl>
+			<GridSplitter Grid.Row="1" Height="4" HorizontalAlignment="Stretch"/>
+			<Grid Grid.Row="2">
+				<local:FunctionsListView x:Name="FunctionsListView" ItemsSource="{Binding Functions, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:MainWindow}}}" SelectionChanged="FunctionsListView_SelectionChanged"/>
+			</Grid>
+		</Grid>
+
+		<GridSplitter Grid.Column="1" HorizontalAlignment="Stretch" Width="4" Grid.RowSpan="2"/>
 	</Grid>
 </Window>
diff --git a/MyExpression.Wpf/MainWindow.xaml.cs b/MyExpression.Wpf/MainWindow.xaml.cs
index 4d9727e..a0741d8 100644
--- a/MyExpression.Wpf/MainWindow.xaml.cs
+++ b/MyExpression.Wpf/MainWindow.xaml.cs
@@ -14,8 +14,12 @@
 using System.Windows.Media.Imaging;
 using System.Windows.Navigation;
 using System.Windows.Shapes;
+using System.Threading;
+using System.Collections.ObjectModel;
+using System.Collections.Specialized;
 
 using MyExpression.Core;
+using System.Globalization;
 
 namespace MyExpression.Wpf
 {
@@ -24,19 +28,8 @@ namespace MyExpression.Wpf
 	/// </summary>
 	public partial class MainWindow : Window
 	{
-		public IList<GraphableFunction> Functions { get; set; } = new List<GraphableFunction>();
-
-		public class GraphableFunction
-		{
-			public IFunctionX Function { get; set; }
-			public FunctionGraph.DrawableFunction GraphFunction { get; set; }
-
-			public GraphableFunction(IFunctionX f, FunctionGraph.DrawableFunction gf)
-			{
-				Function = f;
-				GraphFunction = gf;
-			}
-		}
+		public ObservableCollection<GraphableFunction> Functions { get; private set; } = new ObservableCollection<GraphableFunction>();
+		public GraphableFunction LastFunction { get; private set; }
 
 		public MainWindow()
 		{
@@ -57,8 +50,9 @@ private void Graph_SizeChanged(object sender, SizeChangedEventArgs e)
 			}
 		}
 
-		private void ResetButton_Click(object sender, RoutedEventArgs e)
+		private void InitGraph()
 		{
+
 			try
 			{
 				Graph.Scale = new Point(Double.Parse(ScaleX.Text), Double.Parse(ScaleY.Text));
@@ -74,43 +68,182 @@ private void ResetButton_Click(object sender, RoutedEventArgs e)
 			}
 			catch (Exception ex)
 			{
-				MessageBox.Show(ex.StackTrace, ex.Message);
+				MessageBox.Show(ex.Message + '\n' + ex.StackTrace);
 			}
 		}
 
-		private void DrawButton_Click(object sender, RoutedEventArgs e)
+		private void ResetButton_Click(object sender, RoutedEventArgs e)
+		{
+			InitGraph();
+			Graph.DrawFunctions();
+		}
+
+		//private void DrawButton_Click(object sender, RoutedEventArgs e)
+		//{
+		//	try
+		//	{
+		//		if (Graph.Children.Count == 0)
+		//		{
+		//			throw new ApplicationException("Непроинициализировано");
+		//		}
+		//		Graph.DrawFunctions();
+		//	}
+		//	catch (Exception ex)
+		//	{
+		//		MessageBox.Show(ex.Message + '\n' + ex.StackTrace);
+		//	}
+		//}
+
+		private void AddCodeDomEval()
+		{
+			Cursor = Cursors.Wait;
+			var da = new Interval(Double.Parse(DefinitionAreaLeft.Text), Double.Parse(DefinitionAreaRight.Text));
+			var tpl = (Polynomial.Text, GraphBrushComboBox.SelectedBrush, da);
+			var t = new Task((par) =>
+			{
+				try
+				{
+					var tp = (Tuple<string, SolidColorBrush, Interval>)par;
+					var fp = new CodeDomEval(tp.Item1);
+					Func<double, double> f = fp.Calculate;
+					Graph.Add(f, tp.Item3, tp.Item2);
+					var df = Graph.Functions.Last();
+					Dispatcher.Invoke(() => Functions.Add(LastFunction = new GraphableFunction(fp, df, tp.Item1, Functions)));
+					Dispatcher.Invoke(() => CountLabel.Content = Graph.Count);
+				}
+				catch (Exception ex)
+				{
+					MessageBox.Show(ex.Message + '\n' + ex.StackTrace);
+				}
+				finally
+				{
+					Dispatcher.Invoke(() => Graph.DrawFunctions());
+					Dispatcher.Invoke(() => Cursor = null);
+				}
+			}, tpl.ToTuple());
+			t.Start();
+		}
+
+		private void AddIFunctionX(IFunctionX fp, string formula)
+		{
+			Cursor = Cursors.Wait;
+			var da = new Interval(Double.Parse(DefinitionAreaLeft.Text), Double.Parse(DefinitionAreaRight.Text));
+			Func<double, double> f = fp.Calculate;
+			Graph.Add(f, da, GraphBrushComboBox.SelectedBrush);
+			var df = Graph.Functions.Last();
+			Functions.Add(LastFunction = new GraphableFunction(fp, df, formula, Functions));
+			CountLabel.Content = Graph.Count;
+			Graph.DrawFunctions();
+			Cursor = null;
+		}
+
+		private void AddButton_Click(object sender, RoutedEventArgs e)
 		{
 			try
 			{
-				Graph.DrawFunctions();
+				var t = (string)((ComboBoxItem)TypeComboBox.SelectedValue).Content;
+				if (t == "Auto")
+				{
+					try
+					{
+						AddIFunctionX(Core.Polynomial.Parse(Polynomial.Text), Polynomial.Text);
+					}
+					catch
+					{
+						AddCodeDomEval();
+					}
+				}
+				if (t == "Polynomial")
+				{
+					AddIFunctionX(Core.Polynomial.Parse(Polynomial.Text), Polynomial.Text);
+				}
+				if (t == "CodeDomEval")
+				{
+					AddCodeDomEval();
+				}
+				if (t == "Straight")
+				{
+					var fp = new Straight(Double.Parse(ABox.Text), Double.Parse(BBox.Text));
+					AddIFunctionX(fp, fp.ToString());
+				}
+				if (t == "QuadraticParabola")
+				{
+					var fp = new QuadraticParabola(Double.Parse(ABox.Text), Double.Parse(BBox.Text), Double.Parse(CBox.Text));
+					AddIFunctionX(fp, fp.ToString());
+				}
 			}
 			catch (Exception ex)
 			{
-				MessageBox.Show(ex.StackTrace, ex.Message);
+				MessageBox.Show(ex.Message + '\n' + ex.StackTrace);
 			}
 		}
 
-		private void AddButton_Click(object sender, RoutedEventArgs e)
+		private void ClearButton_Click(object sender, RoutedEventArgs e)
 		{
 			try
 			{
-				var da = new Interval(Double.Parse(DefinitionAreaLeft.Text), Double.Parse(DefinitionAreaRight.Text));
-				IFunctionX fp;
-				try
+				Functions.Clear();
+				LastFunction = null;
+				Graph.Clear();
+				CountLabel.Content = Functions.Count;
+			}
+			catch (Exception ex)
+			{
+				MessageBox.Show(ex.Message + '\n' + ex.StackTrace);
+			}
+		}
+
+		private void SolveButton_Click(object sender, RoutedEventArgs e)
+		{
+			try
+			{
+				var last = FunctionsListView.SelectedFunction;
+				IEquation pe;
+				if (last.Function is Polynomial p)
 				{
-					fp = Core.Polynomial.Parse(Polynomial.Text);
+					pe = new PolynomialEquation(p, Double.Parse(SolveEpsilon.Text));
 				}
-				catch
+				else if (last.Function is CodeDomEval f)
 				{
-					fp = new CodeDomEval(Polynomial.Text);
+					var l = Double.Parse(SolveIntervalLeft.Text);
+					var r = Double.Parse(SolveIntervalRight.Text);
+					var step = Double.Parse(SolveStep.Text);
+					var eps = Double.Parse(SolveEpsilon.Text);
+					pe = new FunctionEquation(f, new Interval(l, r), step, eps);
 				}
+				else
+				{
+					pe = (IEquation)last.Function;
+				}
+				pe.Solve();
+				last.GraphFunction.Roots = new List<double>(pe.Roots);
+				last.GraphFunction.RootsBrush = RootsBrushComboBox.SelectedBrush;
+				RootsTextBox.Text = String.Join("\n", MultipleRootsCheckBox.IsChecked.Value ? pe.AllRoots : pe.Roots);
+				Graph.DrawRoots();
+			}
+			catch (Exception ex)
+			{
+				MessageBox.Show(ex.Message + '\n' + ex.StackTrace);
+			}
+		}
+
+		private void TangentAddButton_Click(object sender, RoutedEventArgs e)
+		{
+			try
+			{
+				var da = new Interval(Double.Parse(DefinitionAreaLeft.Text), Double.Parse(DefinitionAreaRight.Text));
+
+				var fp = new Tangent(FunctionsListView.SelectedFunction.Function, Double.Parse(TangentX.Text), Double.Parse(TangentLim.Text));
 
 				Func<double, double> f = fp.Calculate;
-				Graph.Add(f, da, GraphBrushComboBox.SelectedBrush);
+				Graph.Add(f, da, TangentBrushComboBox.SelectedBrush);
 				var df = Graph.Functions.Last();
-				Functions.Add(new GraphableFunction(fp, df));
+				Functions.Add(new GraphableFunction(fp, df, fp.ToString(), Functions));
+
+				Graph.DrawFunctions();
 
 				CountLabel.Content = Graph.Count;
+
 			}
 			catch (Exception ex)
 			{
@@ -118,35 +251,107 @@ private void AddButton_Click(object sender, RoutedEventArgs e)
 			}
 		}
 
-		private void ClearButton_Click(object sender, RoutedEventArgs e)
+		private void Graph_Loaded(object sender, RoutedEventArgs e)
+		{
+			InitGraph();
+		}
+
+		private void EraseButton_Click(object sender, RoutedEventArgs e)
 		{
 			try
 			{
-				Functions.Clear();
-				Graph.Clear();
-				CountLabel.Content = Functions.Count;
+				var last = FunctionsListView.SelectedFunction;
+				last.GraphFunction.Roots = null;
+				Graph.DrawRoots();
 			}
 			catch (Exception ex)
 			{
-				MessageBox.Show(ex.StackTrace, ex.Message);
+				MessageBox.Show(ex.Message + '\n' + ex.StackTrace);
 			}
 		}
 
-		private void SolveButton_Click(object sender, RoutedEventArgs e)
+		private void FunctionsListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
 		{
 			try
 			{
-				var last = Functions.Last();
-				var p = (Polynomial)last.Function;
-				var pe = new PolynomialEquation(p);
-				pe.Solve();
-				last.GraphFunction.Roots = new List<double>(pe.Roots);
-				Graph.DrawRoots();
+				if (e.RemovedItems.Count == 1)
+				{
+					TangentLim.IsEnabled = true;
+					SolveButton.IsEnabled = false;
+					TangentAddButton.IsEnabled = false;
+				}
+				if (e.AddedItems.Count == 1)
+				{
+					TangentAddButton.IsEnabled = true;
+					var g = (GraphableFunction)e.AddedItems[0];
+					if (g.Function is CodeDomEval)
+					{
+						TangentLim.IsEnabled = true;
+						SolveButton.IsEnabled = true;
+						SolveStep.IsEnabled = true;
+						SolveIntervalLeft.IsEnabled = true;
+						SolveIntervalRight.IsEnabled = true;
+						MultipleRootsCheckBox.IsEnabled = false;
+						if (SolveEpsilon.Text == "1e-15") SolveEpsilon.Text = "1e-6";
+					}
+					else
+					{
+						if (g.Function is Polynomial)
+						{
+							SolveEpsilon.IsEnabled = true;
+						}
+						else
+						{
+							SolveEpsilon.IsEnabled = false;
+						}
+						TangentLim.IsEnabled = false;
+						SolveButton.IsEnabled = true;
+						SolveStep.IsEnabled = false;
+						SolveIntervalLeft.IsEnabled = false;
+						SolveIntervalRight.IsEnabled = false;
+						MultipleRootsCheckBox.IsEnabled = true;
+						if (SolveEpsilon.Text == "1e-6") SolveEpsilon.Text = "1e-15";
+					}
+				}
 			}
 			catch (Exception ex)
 			{
-				MessageBox.Show(ex.StackTrace, ex.Message);
+				MessageBox.Show(ex.Message + '\n' + ex.StackTrace);
+			}
+		}
+
+		private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
+		{
+			try
+			{
+				if (ABox == null) return;
+				var t = (string)((ComboBoxItem)e.AddedItems[0]).Content;
+				if (t == "Auto" || t == "Polynomial" || t == "CodeDomEval")
+				{
+					Polynomial.IsEnabled = true;
+					ABox.IsEnabled = false;
+					BBox.IsEnabled = false;
+					CBox.IsEnabled = false;
+				}
+				if (t == "Straight")
+				{
+					Polynomial.IsEnabled = false;
+					ABox.IsEnabled = true;
+					BBox.IsEnabled = true;
+					CBox.IsEnabled = false;
+				}
+				if (t == "QuadraticParabola")
+				{
+					Polynomial.IsEnabled = false;
+					ABox.IsEnabled = true;
+					BBox.IsEnabled = true;
+					CBox.IsEnabled = true;
+				}
+			}
+			catch (Exception ex)
+			{
+				MessageBox.Show(ex.Message + '\n' + ex.StackTrace);
 			}
 		}
 	}
-}
+}
\ No newline at end of file
diff --git a/MyExpression.Wpf/MyExpression.Wpf.csproj b/MyExpression.Wpf/MyExpression.Wpf.csproj
index 3f8211b..ff3fd14 100644
--- a/MyExpression.Wpf/MyExpression.Wpf.csproj
+++ b/MyExpression.Wpf/MyExpression.Wpf.csproj
@@ -14,6 +14,7 @@
     <WarningLevel>4</WarningLevel>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
     <TargetFrameworkProfile />
+    <ApplicationIcon>..\MyExpression.Wpf\Icons\Icon1.ico</ApplicationIcon>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -65,6 +66,8 @@
     </Compile>
     <Compile Include="BrushesList.cs" />
     <Compile Include="FunctionGraph.cs" />
+    <Compile Include="FunctionsListView.cs" />
+    <Compile Include="GraphableFunction.cs" />
     <Compile Include="MainWindow.xaml.cs">
       <DependentUpon>MainWindow.xaml</DependentUpon>
       <SubType>Code</SubType>
diff --git a/MyExpression.Wpf/Screenshot.png b/MyExpression.Wpf/Screenshot.png
new file mode 100644
index 0000000..4c03051
Binary files /dev/null and b/MyExpression.Wpf/Screenshot.png differ
diff --git a/README.md b/README.md
index 8b26102..0829e30 100644
--- a/README.md
+++ b/README.md
@@ -4,3 +4,32 @@
 | `latest` | [![Build status](https://ci.appveyor.com/api/projects/status/y44s4vmjr7nvnyk0?svg=true)](https://ci.appveyor.com/project/prekel/myexpression) |
 | `master` | [![Build status](https://ci.appveyor.com/api/projects/status/y44s4vmjr7nvnyk0/branch/master?svg=true)](https://ci.appveyor.com/project/prekel/myexpression/branch/master) |
 | `develop` | [![Build status](https://ci.appveyor.com/api/projects/status/y44s4vmjr7nvnyk0/branch/develop?svg=true)](https://ci.appveyor.com/project/prekel/myexpression/branch/develop) |
+
+## Решение алгебраических уравнений любой степени с заданной точностью
+```c#
+var s = "x^3-2x^2-x+2";
+var eps = 1e-8;
+var p = Polynomial.Parse(s);
+var e = new PolynomialEquation(p, eps);
+e.Solve();
+Assert.AreEqual(-1, e.Roots[0], 1e-7);
+Assert.AreEqual(0, p.Calculate(e.Roots[0]), 1e-7);
+Assert.AreEqual(1, e.Roots[1], 1e-7);
+Assert.AreEqual(0, p.Calculate(e.Roots[1]), 1e-7);
+Assert.AreEqual(2, e.Roots[2], 1e-7);
+Assert.AreEqual(0, p.Calculate(e.Roots[2]), 1e-7);
+```
+
+## Создание функции из строки
+```c#
+var s = "sin(x)";
+var c = new CodeDomEval(s);
+Func<double, double> f = c.Calculate;
+Assert.AreEqual(0, f(0), 1e-7);
+Assert.AreEqual(1, f(Math.PI / 2), 1e-7);
+Assert.AreEqual(0, f(Math.PI), 1e-7);
+Assert.AreEqual(Math.Sqrt(2) / 2, f(Math.PI / 4), 1e-7);
+```
+
+## Графический интерфейс для этого и постройка графиков
+![Build status](MyExpression.Wpf/Screenshot.png)
diff --git a/appveyor.yml b/appveyor.yml
index a48e79f..ec55e01 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,4 +1,4 @@
-version: 0.2.{build}
+version: 0.3.{build}
 image: Visual Studio 2017
 configuration: Release
 platform: Any CPU
@@ -43,7 +43,7 @@ deploy:
   description: $(appveyor_repo_tag_name) $(assembly_version)
   auth_token:
     secure: Npd8Pdh2luH0INNPoAQXoPC2g71ZM39Ys1Cu842ZZaRFt6B45Or6vy1bV10x0oSn
-  artifact: MyExpression; MyExpression.Core.dll; MyExpression.Console.exe; MyExpression.Wpf; MyExpression_All_Files
+  artifact: MyExpression; MyExpression_All_Files
   draft: false
   prerelease: true
   on:
@@ -55,7 +55,7 @@ deploy:
   description: $(appveyor_repo_tag_name) $(assembly_version)
   auth_token:
     secure: Npd8Pdh2luH0INNPoAQXoPC2g71ZM39Ys1Cu842ZZaRFt6B45Or6vy1bV10x0oSn
-  artifact: MyExpression; MyExpression.Core.dll; MyExpression.Console.exe; MyExpression.Wpf; MyExpression_All_Files
+  artifact: MyExpression; MyExpression_All_Files
   draft: false
   prerelease: false
   on: