How do I solve this other than using sin^2+cos^2=1?

Answer 1

Possibly you mean how to solve the equation (sinx)^2 + (cosx)^2 = 1 ?? If you try to solve that equation for x, x can equal any angle, as the equation is an identity, always true for any x. It's a tautology, like x = x. Try to solve for x, and x can be any number, between negative and positive infinity.