Indefinite Integrals

Abstract

There are a lot of integration rules. Look through them all. Some of them will seem trivial if you've seen the differentiation rules.

  • Trig identities are useful
  • Guessing and fixing: usually, in the case of composition, we may try to integrate the first function. Then, differentiating it, we find extra coefficients moved out, so we have to include the inverse of those.
  • Always a good idea to verify by differentiation
Definition

The indefinite integral of is the collection of all possible antiderivatives. We denote if by:

Integration Rules

Reverse of differentiation rules

Example

Example - Guess and Fix Up

Evaluate

We guess that this involves . But , so all we need to do it account for the 2

Check your answer

Example

Evaluate .
We need the half angle identity

Example

Evaluate