Cosine

cos x     cos[x]

Where x is a numeric, returns the cosine of x, taken to be in radians. The result is between -1 and 1, or null if the argument is null or infinity.

q)cos 0.2                       / cosine
0.9800666
q)min cos 10000?3.14159265
-1f
q)max cos 10000?3.14159265
1f