Until now, every integral we cared to solve was (relatively) easy to evaluate using an integration rule. Honestly, that has been a bit unrealistic, but we have to, as Drake would say, start from the bottom. This video takes a step back to using the Chain Rule to find the derivative of a function. The lesson seeks to rewind that process. Duration: 5:00

While it's easy enough to see that a given integrand is a composite function, it's not always as simple to reverse the Chain Rule to find its antiderivative. To help simplify the process, we use the Substitution Rule, where the interior function becomes, essentially, a single variable. Duration: 11:27