Trigonometric Functions

[rkalapura]

Hi,


I want to do some calculations using trigonometric functions in a unbound text box in a form in Access 2010. But it is not giving me the right value. I think by default access gives the value in Radians. Text box formatted to 3 decimals. For example, when I enter =Sin(30) in the text box it gives me -0.988 but I need to have the value in degrees and I know that it is 0.500. Same way when I enter =Cos(30) in the box, it gives me .154, where as actual value of Cos(30) degree is 0.866. Help menu gives the following statement:

"To convert degrees to radians, multiply degrees by pi/180. To convert radians to degrees, multiply radians by 180/pi." This gives close but not exact.

How can I format my text box or set access to get the value in degree?

Thank you in advance for your help and advise.

[ItsMe]

I am not an expert, but this is the result I get.

Dim dblCos As Double
Dim dblAngleRad As Double
Dim dblAngleDeg As Double
dblAngleDeg = 30
dblAngleRad = dblAngleDeg * (3.14159 / 180)
Debug.Print "dblAngleRad = " & dblAngleRad
dblCos = 1 / Sin(dblAngleRad)
Debug.Print "dblCos in Radians = " & dblCos
dblCos = dblCos * (180 / 3.14159)
Debug.Print "dblCos in Degrees = " & dblCos

Results in
dblAngleRad = 0.523598333333333
dblCos in Radians = 2.00000153205215
dblCos in Degrees = 114.591743597792

[June7]

The number argument must be in radians. If 30 is degress, then:

Cos(30 * (3.14159/180)) = 0.866025624916837

The value returned by trig function is a ratio.

[ssanfu]

PMFJI,

I was playing around and came up with this function.

Lets say you have 3 unbound text boxes on a form.

In design view, name
the first text box "tbTheAngle"; change the label caption to "Angle"
the second text box "tbSine"; change the label caption to "Sine"
and the third text box "tbCosine"; change the label caption to "Cosine"

Paste the following function into a standard module:

Function GetSinCos(pTFunction As String, pdAngle As Double) As Double
   Const dPi As Double = 3.14159265358979

   Dim dRadians As Double
   Dim dResult As Double

   dResult = 0

   'convert Degrees to Radians
   dRadians = pdAngle * (dPi / 180)

   Select Case pTFunction
      Case "Sine"
         'calc Sine
         dResult = Sin(dRadians)

      Case "Cosine"
         'Calc Cosine
         dResult = Cos(dRadians)
         
      Case Else
         MsgBox "Not Sine or Cosine"
   End Select

   GetSinCos = dResult

End Function

In the control source for the text box "tbSine", enter
=GetSinCos("Sine",[tbTheAngle])

In the control source for the text box "tbCosine", enter
=GetSinCos("Cosine",[tbTheAngle])

Switch the form to standard view and enter 30 into the top text box (tbAngle).

The value returned for the Sine should be 0.5
and the value for the Cosine should be 0.866025403784439