U-Substitution Definition
U-Substitution also known as integration by substitution, or substitution method, is an integration method for evaluating integrals. Direct application of the fundamental theorem of calculus to find an antiderivative can be quite difficult, and integration by substitution can help simplify that task. It is the counterpart to the chain rule for differentiation, in other words, it can loosely be thought of as using the chain rule backwards.
Sources
“Integration by Substitution.” Wikipedia, Wikimedia Foundation, 19 May 2020, en.wikipedia.org/wiki/Integration_by_substitution.
