Integration Decision Making (Edexcel IAL Maths)

Decision Making

Integration decision making

What is integration 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) $\frac{f'(x)}{f(x)}$

(7) Partial fractions

(8) Integration by Parts

(9) Reverse Chain Rule

Exam Hint

• 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.

Worked Example