Функция с RadioButton - Visual Basic .NET

Формулировка задачи:

Короче говоря задача есть такая: найти значение функции при выбранных значениях х y z. при этом надо выбрать чему будет равно k в радиобаттон. либо sh(x) либо e^x либо x^2 Сама функция и как должна форма выглядеть во вложениях В чем заключается проблема: вбиваю код и выдает одно и то же значения вне зависимости от выбора в радиобаттон. не пойму в чем ошибся

Public Class Form1
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
       
    End Sub
 
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        TextBox1.Text = ""
        TextBox2.Text = ""
        TextBox3.Text = ""
        TextBox4.Text = ""
    End Sub
 
    Private Sub TextBox4_TextChanged(sender As Object, e As EventArgs) Handles TextBox4.TextChanged
 
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim x As Double = Double.Parse(TextBox1.Text)
        Dim k As Double
        Dim y As Double = Double.Parse(TextBox2.Text)
        Dim z As Double = Double.Parse(TextBox3.Text)
                    TextBox4.Text = "Результаты работы программы ст. Хусаинова:"
                    TextBox4.Text += vbNewLine + "При X=" + x.ToString()
                    TextBox4.Text += vbNewLine + "При Y=" + y.ToString()
                    TextBox4.Text += vbNewLine + "При Z=" + z.ToString()
                    Dim n As Double = (Math.Min(k + y, y - z)) / (Math.Max(k, y))
        TextBox4.Text += vbNewLine + "n = " + n.ToString()
 
    End Sub
 
    Private Sub RadioButton1_CheckedChanged(sender As Object, e As EventArgs) Handles RadioButton1.CheckedChanged
        Dim k As Double
        Dim x As Double = Double.Parse(TextBox1.Text)
        If RadioButton1.Checked = True Then
            k = Math.Sinh(x)
        End If
    End Sub
 
    Private Sub RadioButton2_CheckedChanged(sender As Object, e As EventArgs) Handles RadioButton2.CheckedChanged
        Dim k As Double
        Dim x As Double = Double.Parse(TextBox1.Text)
        If RadioButton2.Checked = True Then
            k = x ^ 2
        End If
    End Sub
 
    Private Sub RadioButton3_CheckedChanged(sender As Object, e As EventArgs) Handles RadioButton3.CheckedChanged
        Dim k As Double
        Dim x As Double = Double.Parse(TextBox1.Text)
        If RadioButton3.Checked = True Then
            k = Math.Exp(x)
        End If
    End Sub
End Class

Решение задачи: «Функция с RadioButton»

textual
                            Листинг программы 
                        

                            Public Class Form1
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
       
    End Sub
 
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        TextBox1.Text = ""
        TextBox2.Text = ""
        TextBox3.Text = ""
        TextBox4.Text = ""
    End Sub
 
    Private Sub TextBox4_TextChanged(sender As Object, e As EventArgs) Handles TextBox4.TextChanged
 
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim x As Double = Double.Parse(TextBox1.Text)
        Dim k As Double
        Dim y As Double = Double.Parse(TextBox2.Text)
        Dim z As Double = Double.Parse(TextBox3.Text)
        If RadioButton1.Checked = True Then
            k = Math.Sinh(x)
        ElseIf RadioButton2.Checked = True Then
            k = x ^ 2
        ElseIf RadioButton3.Checked = True Then
            k = Math.Exp(x)
        End If
 
 
        TextBox4.Text = "Результаты работы программы ст. Хусаинова:"
        TextBox4.Text += vbNewLine + "При X=" + x.ToString()
        TextBox4.Text += vbNewLine + "При Y=" + y.ToString()
        TextBox4.Text += vbNewLine + "При Z=" + z.ToString()
        Dim n As Double = (Math.Min(k + y, y - z)) / (Math.Max(k, y))
        TextBox4.Text += vbNewLine + "n = " + n.ToString()
 
    End Sub
 
    Private Sub RadioButton1_CheckedChanged(ByVal sender As Object, e As EventArgs) Handles RadioButton1.CheckedChanged
        
    End Sub
 
    Private Sub RadioButton2_CheckedChanged(ByVal sender As Object, e As EventArgs) Handles RadioButton2.CheckedChanged
 
    End Sub
 
    Private Sub RadioButton3_CheckedChanged(ByVal sender As Object, e As EventArgs) Handles RadioButton3.CheckedChanged
 
    End Sub
End Class
                        