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# Cos Function

Calculates the cosine of an angle. The angle is specified in radians. The result lies between -1 and 1.

Using the angle Alpha, the Cos-Function calculates the ratio of the length of the side that is adjacent to the angle, divided by the length of the hypotenuse in a right-angled triangle.

Cos(Alpha) = Adjacent/Hypotenuse

## Syntax:

    Cos (Number)

## Return value:

Double

## Parameters:

Number: Numeric expression that specifies an angle in radians that you want to calculate the cosine for.

To convert degrees to radians, multiply degrees by pi/180. To convert radians to degrees, multiply radians by 180/pi.

degree=(radian*180)/pi

radian=(degree*pi)/180

Pi is here the fixed circle constant with the rounded value 3.14159...

### Error codes:

5 Invalid procedure call

## Example:

    REM The following example allows for a right-angled triangle the input of
    REM secant and angle (in degrees) and calculates the length of the hypotenuse:
    Sub ExampleCosinus
    REM rounded Pi = 3.14159
    Dim d1 As Double, dAngle As Double
        d1 = InputBox$ (""Enter the length of the adjacent side: ","Adjacent")
        dAngle = InputBox("Enter the angle Alpha (in degrees): ","Alpha")
        Print "The length of the hypothenuse is"; (d1 / cos (dAngle * Pi / 180))
    End Sub