Originally Posted by

**zortharg** Hold on there trogdorkilla, your first function is the regular sin function and has a domain from 0 to pi/2 and a range of 0 to 1, but the second one USES THE FIRST as an input but it too has a domain from 0 to pi/2. The problem is, the first function doesn't have a range extending to pi/2, it has a range extending to 1. The first function is not onto [0,pi/2] so the second can't be defined over that whole range, it can only be defined from [0,1] and the third can only be defined over [0,sin(1)] and the fourth over [0,sin(sin(1))].