Hi I'm looking for help with a simple question in calculus. The question is: how do you differentiate the integral of a composite function? Specifically, if what is ?

The closest thing to an answer I could find was Leibniz's rule, which suggested the answer should be , but the answer I should get (according to someone else's notes) is just , as if the integral isn't there.

I actually think there might not be an answer, i.e. there may be some hand-waving going on. I would be grateful if someone could confirm if that's the case. If there is a rule that applies to this situation, I would be grateful if someone could explain.

Thanks.