What is meant by integration and decision making?
- The hardest part of integration is deciding which technique to use
- There are lots of them!
How do I know which integration method to use?
- The main two requirements for success with integration are
- Experience
- Familiarity
- Always check for Reverse Chain Rule …
- … particularly after changing part of an integral …
- … by using a trig identity for example

Key to diagram above:
(1) Powers of x (2) Substitution
(3) Obvious substitution (4) Trig
(5) Algebraic Division (6) f’(x) / f(x)
(7) Partial fractions (8) Integration by Parts
(9) REVERSE CHAIN RULE
Exam Tip
If in doubt, try something … You may gain marks for attempting a suitable substitution. You may gain marks from using a trig identity. You may gain marks from attempting to simplify or rewrite a fraction.