I'm in my first semester of calculus, so the problems I'm facing are about as hard as those on KhanAcademy calculus playlist. I'm currently doing integration, a somewhat difficult part of the course. Doing derivatives is mechanics; finding the integral is an art.
The two main techniques showed are
- integration by parts
My question is: are there any rules of thumb (preferably with a logical reason behind it) of when to use which?