# more integration!

• Jan 21st 2010, 06:31 PM
littlesohi
more integration!
1. $\int x^2sin2x dx$

2. $\int (x+3)/(x+1)$
• Jan 21st 2010, 06:33 PM
Jhevon
Quote:

Originally Posted by littlesohi
1. $\int x^2sin2x dx$

Hint: integration by parts: $u = x^2, ~dv = \sin 2x dx$ (you will have to do integration by parts twice.

Quote:

2. $\int (x+3)/(x+1)$
Hint: Note that this is $\int \frac {x + 1 + 2}{x + 1}~dx = \int \left( 1 + \frac 2{x + 1} \right)~dx$