# Integrate sin x cos^n x

• May 7th 2011, 06:11 PM
anees7112
Integrate sin x cos^n x
Hello :)

Q) ∫ sin x cos^n x dx

If you could let me know which identity to use that would be a great help.

Thank you.
• May 7th 2011, 06:18 PM
TheEmptySet
Quote:

Originally Posted by anees7112
Hello :)

Q) ∫ sin x cos^n x dx

If you could let me know which identity to use that would be a great help.

Thank you.

Use the substition

$u = \cos(x) \implies du=-\sin(x)$

This gives the integral

$-\int u^ndu$
• May 7th 2011, 06:25 PM
anees7112
Ah I see. Thank you very much, TheEmptySet! :)