Syntax: COS(X)
X = a numeric value expressed in radians.
COS returns the cosine of angle X. The result is between -1 and 1. (To convert the argument from degrees to radians, use the RADIANS function.)
Examples:
COS(-45) = 0.52532199
COS(K24) = 0.5403023, where K24 = 1
COS(RADIANS(30)) = 0.866025
Excel function: COS