Hello MHF, please help me with this problem

But isnt correct, i'm afraid my substitution is not correct

Printable View

- Nov 13th 2012, 02:35 PMChipset3600direct integration
Hello MHF, please help me with this problem

But isnt correct, i'm afraid my substitution is not correct - Nov 13th 2012, 03:40 PMMarkFLRe: direct integration
If your original integral is:

I would first factor the integrand:

Now, let:

and the integral becomes:

Now, find the anti-derivative, then back-substitute for . - Nov 13th 2012, 03:43 PMChipset3600Re: direct integration
- Nov 13th 2012, 03:47 PMMarkFLRe: direct integration
- Nov 13th 2012, 03:51 PMChipset3600Re: direct integration
- Nov 13th 2012, 09:00 PMhollywoodRe: direct integration
This is a difficult integral for someone who hasn't learned about u-substitution yet. You're probably aware that the derivative of is . And looking at the other term might eventually lead you to take the derivative of . Once you do that, you should be able to combine the two derivatives to get the expression you want to integrate.

It's probably less work to first learn u-substution, then apply it to this integral. But I guess that's not an option for you.

- Hollywood - Nov 15th 2012, 01:29 PMChipset3600Re: direct integration
Actually isnt so hard, take a look:

Now i use the power rule for the first and the sec^2(u) rule for the second integral

Now take a look of the derivative of my answer: Attachment 25734