The question:

Find

My attempt:

Let u =

Find bounds in terms of u...

Sub 1 into u:

Sub 0 into u:

However, the answer is 15/4. :/

What am I doing wrong? Thanks!

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- October 26th 2010, 03:10 AMGlitchDefinite integral problem
**The question:**

Find

**My attempt:**

Let u =

Find bounds in terms of u...

Sub 1 into u:

Sub 0 into u:

However, the answer is 15/4. :/

What am I doing wrong? Thanks! - October 26th 2010, 03:15 AMPlato
What is the derivative of

- October 26th 2010, 03:20 AMGlitch
- October 26th 2010, 03:41 AMPlato
Well there you have it. Do you not?

- October 26th 2010, 03:45 AMGlitch
Not really, because you've solved the integral and I just proved it. I can't always make that leap like you did, which is why I tried the substitution method to help me. I'm still not sure what I've actually done wrong.

- October 26th 2010, 03:50 AMearboth
- October 26th 2010, 03:53 AMGlitch
Nevermind, I was finding the derivative of u^3 instead of the anti-derivative like an idiot. All solved.

EDIT: Yeah, just realised earboth. Thanks.