There are math functions in mcScript, they are part of the Float object which is documented in the mcScript User Guide (section 5.2.6 and 16.6).

See sample code below:

Dim someFloat As Float = 81
Dim someFloat2 As Float = 90
Dim sqrtOfFloat As Float = someFloat.Sqrt
Dim sinOfFloat As Float = someFloat2.Sin
Dim cosOfFloat As Float = someFloat2.Cos
Note: Sin and Cos are in Radians.