Evaluate the definite integral:
Finding the derivative gives me this, which is confirmed by the steps in Wolfram Alpha. This is the answer as the last step that I also got.
But then at the top, Wolfram Alpha says the answer is this:
How did they get that?
Edit: I just realized that I'm solving the question wrong; I'm supposed to find the antiderivative and not the derivate. Either way, I wanted to know how the identity was found.