x Turn on thread page Beta
 You are Here: Home >< Maths

C3 - Intergration by parts watch

1. My brain literally stopped working... How would you integrate xlnx ? I'm guessing by parts?

Can someone post a written solution step by step

Posted from TSR Mobile
2. u = lnx
dv/dx = x

stick it in the formula
3. one way is if you have:

so, use

and

plug in and integrate last part...

(if you choose u and v the other way around, you have to know that the integral of ln(x) = xln(x)-x, and the parts bit gets messy)
4. so u=lnx du/dx = 1/x

dv/dx = x dv/dx = x^2/2

subsitute it into the formula, the last part gives me: intergrate x/2... is that just xln2 if you intergrate x/2?
5. (Original post by Gary)
intergrate x/2... is that just xln2 if you intergrate x/2?
No

Hint:

And I'm sure you can integrate that.
6. I'm sure this is C4?
7. (Original post by usycool1)
No

Hint:

And I'm sure you can integrate that.
Oh yeh of course -.- I hate myself at times ....

Posted from TSR Mobile
8. (Original post by nm786)
I'm sure this is C4?
It's C4 for Edexcel but other exam boards (like AQA, IIRC) have integration in C3.
9. you make lnx = u and make x= dv/dx, natural logs take priority over polynomials never forget that. Dont forget to integrate ln(x) on its own you do u=lnx and dv/dx= 1
10. (Original post by usycool1)
It's C4 for Edexcel but other exam boards (like AQA, IIRC) have integration in C3.
alright cool.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: April 16, 2013
Today on TSR

Loughborough better than Cambridge

Loughborough at number one

Poll
Useful resources

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

How to use LaTex

Writing equations the easy way

Study habits of A* students

Top tips from students who have already aced their exams

Chat with other maths applicants