This one can be a little tricky. Use integration by parts.

Let

Therefore:

Let

The integral portion becomes

Can you finish up now?.

Results 1 to 5 of 5

- July 30th 2006, 04:50 AM #1

- Joined
- Jul 2006
- From
- Singapore
- Posts
- 55

## I need help again!

Okay, this question is making me confused.

(i) State the derivative of sin(x^2).

I got that correct but I can't get the next part.

(ii) Find (integrate) x^3 cos (x^2) dx.

Answer: 1/2 [x^2 sin (x^2) + cos (x^2)] + C.

Thanks in advance if you could help!

- July 30th 2006, 05:57 AM #2

- July 30th 2006, 06:49 AM #3

- Joined
- Jul 2006
- From
- Singapore
- Posts
- 55

- July 30th 2006, 08:36 AM #4

- July 31st 2006, 05:20 AM #5

- Joined
- Jul 2006
- From
- Singapore
- Posts
- 55