PostScript command to calculate the cosine of a number. Pops the top entry of the stack and returns the cosine of the number, treated as an angle in degrees. Leaves the result on the top of the stack.

Example:

%!PS
0 0 moveto
100 0 lineto
0 0 moveto
100 45 cos mul 100 45 sin mul lineto
stroke
showpage
quit

CoS is a common abbreviation for the Church of Scientology, a religion started by L. Ron Hubbard on a bet with another Sci-fi writer, some say. Oftentimes to illustrate the costly nature of becoming a Scientologist, the S is replaced with a dollar sign, becoming Co$.