# Using trig substitution or partial fractions?

1. May 12, 2014

### JessicaJ283782

When would you use trig substitution vs. partial fractions? I know partial fractions is when you have a polynomial over a polynomial, but some of the problems in the trig substitution section in my book had polynomial over polynomial and used trig substitution?

2. May 12, 2014

### alan2

A good general rule is that any time you see the sum or difference of 2 squares you should think trig substitution. The sum or difference of 2 squares looks like the Pythagorean theorem so you have a right triangle. Label an angle and express all terms as trigonometric functions of that angle. There certainly are multiple methods for many integrations.

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook