Differentiate and verify that it is equal to .
Hi, my teacher gave me this proof to do for homework but I can't figure out where to even start. He wants us to prove that ∫du/(a^2+u^2 ) = 1/a arctan〖u/a〗+C, and also the same thing for the similar arcsin identity. He also said to use differentiation to prove this. Not really sure what to do.