Lesser-known integration tricks

I am currently studying for the GRE math subject test, which heavily tests calculus. I’ve reviewed most of the basic calculus techniques (integration by parts, trig substitutions, etc.) I am now looking for a list or reference for some lesser-known tricks or clever substitutions that are useful in integration. For example, I learned of this trick

baf(x)dx=baf(a+bx)dx

in the question Showing that aaf(x)1+exdx=a0f(x)dx, when f is even

I am especially interested in tricks that can be used without an excessive amount of computation, as I believe (or hope?) that these will be what is useful for the GRE.

Answer

I don’t know about “lesser known” but many calculus courses pass over hyperbolic functions. Just as the identity sin2(t)+cos2(t)=1 allows one to deal with 1x2 terms, the identity cosh2(t)sinh2(t)=1 allows one to deal with 1+x2 terms.

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