No, no, no and no. Never, EVER do that again. sin(x) is a function. It is not a modifier. Never, ever, split up its argument like that. Ever. "sin" means nothing - except in a religious sense. "sin" must have an argument.= sin^2x - sin x + .... (i dont know how to multiply sin with 1, is it just sin(1) ?)
Didn't we do g(f(x)) already in the Domain and Range question?