# Integration Clarification

• Jun 2nd 2008, 10:18 PM
Evales
Integration Clarification
Haha I just realised that its exam season, have you guys been getting a lot more questions?

Anyway
In some notes that I found on the my schools site there is a rule of sorts to working out what to do when integrating trig.

[sin(x)]^n . dx

It then says that if n is even "change to mulitple angles" What does it mean by multiple angles?

Thanks!
• Jun 2nd 2008, 10:27 PM
Moo
Hello,

Quote:

Originally Posted by Evales
Haha I just realised that its exam season, have you guys been getting a lot more questions?

Anyway
In some notes that I found on the my schools site there is a rule of sorts to working out what to do when integrating trig.

[sin(x)]^n . dx

It then says that if n is even "change to mulitple angles" What does it mean by multiple angles?

Thanks!

Multiple-Angle Formulas -- from Wolfram MathWorld :D

If n is even, you can write : $n=2n'$, $\sin^nx=\left(\sin^2x\right)^{n'}=\left(\frac{1-\cos 2x}{2}\right)^{n'}$