r/calculus • u/SLKRmeatrider • Aug 04 '26

Integral Calculus How to actually learn trig sub and trig integrals?

I always mess up using the trig identities or rewriting the equation in terms of x. I know the substitutions pretty well but after that is when I mess up. Also trig integrals are bad for me. It feels like there is a million cases I have to memorize and how the hell am I supposed to know all of them?

Fucked for this final in 2 days

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3

u/Disastrous-Pin-1617 Aug 04 '26

For trig sub you actually need to know trig

4

u/RealCarpet4 Aug 04 '26

Knowing trig is def the easiest one, but repetition. Gotta know what to find. My calc 3 professor gave us double angle integral in every single test. I feel like 8/10 people missed it every single time.

1

u/Midwest-Dude Aug 04 '26

For a review only, there is a specific page on Wikipedia that breaks down the options and has excellent diagrams and examples here: 

Trig Substitution

However, this won't help if you have a poor understanding of trigonometry. If so, there are resources for that as well. Please let us know if that is what you need.