[RESOLVED] Calculating Trigonometrical formulas

[.paul.]

This is a small calculator i'm writing. I just need help with VB.Net formulas for cotangent, secant, and cosecant.
Given an angle (NumericUpDown1.Value), how would i complete this code?

Private Sub calculate()
    Select Case ComboBox1.SelectedIndex
        Case 0 ' sine(sin)
            Label3.Text = $"Math.Sin({NumericUpDown1.Value})"
            Label4.Text = Math.Sin(NumericUpDown1.Value).ToString
        Case 1 ' cosine(cos)
            Label3.Text = $"Math.Cos({NumericUpDown1.Value})"
            Label4.Text = Math.Cos(NumericUpDown1.Value).ToString
        Case 2 ' tangent(tan)
            Label3.Text = $"Math.Tan({NumericUpDown1.Value})"
            Label4.Text = Math.Tan(NumericUpDown1.Value).ToString
        Case 3 ' cotangent(cot)
            Label3.Text = $"1 / Math.Tan({NumericUpDown1.Value})"
            Label4.Text = 1 / Math.Tan(NumericUpDown1.Value).ToString '???
        Case 4 ' secant(sec)
            Label3.Text = ""
            Label4.Text = "" '???
        Case 5 ' cosecant(csc)
            Label3.Text = ""
            Label4.Text = "" '???
        Case Else ' -1
            Label3.Text = ""
            Label4.Text = ""
    End Select
End Sub

I'm just testing this now. Should the angle be given in Radians?

[OptionBase1]

Secant = 1/Cosine
Cosecant = 1/Sin


Of course, because both Sin and Cosine can equal 0 for theta=2n*pi and theta=2*(n+1)*pi, respectively, and where n is any integer, you need to code around "1/0" situations.

[2kaud]

cotangent = cosine/sine (instead of tangent which is sine/cosine)

[.paul.]

Thanks to both of you. I'll do some testing before i mark this resolved...

[Arnoutdv]

And for working with angles in degrees instead of radians:

Dim angleRadians As Double = angleDegrees * Math.PI / 180
Dim sinValue As Double = Math.Sin(angleRadians) 
Dim cosValue As Double = Math.Cos(angleRadians)
Dim tanValue As Double = Math.Tan(angleRadians)

Dim cot As Double = 1 / tanValue 
Dim sec As Double = 1 / cosValue 
Dim csc As Double = 1 / sinValue