Editing Trigonometric substitution (section)

{{short description|Technique of integral evaluation}}
{{Trigonometry}}
{{calculus|expanded=integral}}
In [[mathematics]], a '''trigonometric substitution''' replaces a [[trigonometric functions|trigonometric function]] for another expression. In [[calculus]], trigonometric substitutions are a technique for evaluating integrals. In this case, an expression involving a [[Radical expression|radical function]] is replaced with a trigonometric one. Trigonometric identities may help simplify the answer.<ref>{{cite book | last=Stewart | first=James | author-link=James Stewart (mathematician) | title=Calculus: Early Transcendentals | publisher=[[Brooks/Cole]] | edition=6th | year=2008 | isbn=978-0-495-01166-8 | url-access=registration | url=https://archive.org/details/calculusearlytra00stew_1 }}</ref><ref>{{cite book | last1 = Thomas | first1 = George B. | last2=Weir | first2= Maurice D. | last3=Hass | first3=Joel | author3-link = Joel Hass | author-link=George B. Thomas | title=Thomas' Calculus: Early Transcendentals | publisher=[[Addison-Wesley]] | year=2010 | edition=12th | isbn=978-0-321-58876-0}}</ref> Like other methods of integration by substitution, when evaluating a definite integral, it may be simpler to completely deduce the antiderivative before applying the boundaries of integration.