Integration using Trig identities
Last updated
Last updated
The goal is to convert the multiplication of terms to be addition of simple terms.
▶ Cheatsheet on previous note: Basic Integral Rules ▶ Cheatsheet on previous note:Basic Differential Rules ▶ Cheatsheet on previous note: All trig identities ▶ Back to previous note on: U-substitution → Chain Rule
Refer to Khan academy: Integrating using trigonometric identities
Solve:
We can identify there's a Integral trig rule we can apply on this problem:
Therefore we're gonna organize it a bit with u-substitution and get the answer:
Solve:
This integrand has an odd power of sin(x), so we're gonna leave sin(x) alone and make an even power for sin(x), then make u-substitution upon it:
And also we need to change the boundaries for the integral:
Now we can start to integrate:
We're gonna use a trig-integral-rule and a trig identity:
Then apply them:
Solve:
