Microsoft® Visual Basic® Scripting Edition Cos Function 
Language Reference Version 1

Returns the cosine of an angle.
Cos(number)The number argument can be any valid numeric expression that expresses an angle in radians.
The Cos function takes an angle and returns the ratio of two sides of a right triangle. The ratio is the length of the side adjacent to the angle divided by the length of the hypotenuse.The result lies in the range 1 to 1.
To convert degrees to radians, multiply degrees by pi/180. To convert radians to degrees, multiply radians by 180/pi.