Fubini's Theorem Magic, Quiz 5 Problem 2

We compute an iterated double integral that is fairly difficult as written because the integrand does not have an elementary antiderivative with respect to x. By employing Fubini's theorem to reverse the order of integration, we can antidifferentiate first with respect to y, yielding a second antiderivative problem that can be solved with a simple substitution. For another example, see: https://youtu.be/TdTrCLrr8N0