Won't the derivative of -5 equal 0?
That doesn't make much sense, though. Something's wrong.
What do you do for this?
the derivative of a constant is zero. where do you see a constant here? 5 is a power, for all intents and purposes, it is a part of the sine function we are dealing with. if it was just a 5 by itself, then yes, it goes to zero, that is not the case here. use the chain rule (with the power rule)