<p>I know that there will be some trig integral questions on the tests and I probably already know the answer but do I really need to know all the formulas? (IE: double angles and such..) I know most of them are similar and can be related, but I just don't want to memorize this crap if I don't need to. I'm under the impression i probably will need to do some substituting just to transform the integral into something I can integrate. Can anyone can confirm or dney or offer their beliefs?(the only one i know by heart is sin²x+cox²x=1 >_>)</p>
<p>Another thing is the integral and deriverative of anything past arc tan and arc sin...</p>
<p>You want to know arc cos and arc sec as well. As for trig substitutions… those are irrelevant, and IF the there is a question that requires trig sub then it might be 1 question and most and you’re better off studying something else. However, if you’d like to master the material (keeping in mind that trig substitutions are useful to derive formulas) then I say go for it.</p>
<p>Just know the basics… I didn’t use a double angle but maybe one time this year. I learned them all in pre-calc last year, then forgot over the summer (of course). There’s not enough problems on the test that require trig to make it worth your time to memorize them. :-)</p>
<p>I think the trig you need to know cold is the power-reducing formulas for sin^2 and cos^2. Often, these will be the result of integration by parts or trig substitution, so you need these formulas to continue.</p>