You are Here: Home

# integral problem watch

1. hi, how do i evaluate integral of (-x^3)/(x+1)^2 dx ?
i would use substitution or split it in more parts but i dont know how??? can anybody show me how to do it? thanks
2. (Original post by gomer)
hi, how do i evaluate integral of (-x^3)/(x+1)^2 dx ?
i would use substitution or split it in more parts but i dont know how??? can anybody show me how to do it? thanks
Integration by parts appears to be a better option in my opinion..
3. (Original post by gomer)
hi, how do i evaluate integral of (-x^3)/(x+1)^2 dx ?
i would use substitution or split it in more parts but i dont know how??? can anybody show me how to do it? thanks
Try long division, to get a quotient and a remainder that isn't top-heavy, then you can integrate.
4. (Original post by XTinaA)
Try long division, to get a quotient and a remainder that isn't top-heavy, then you can integrate.
OK, that seems to be good idea , thank you
5. ∫ -x³/(x+1)² dx
x³/(x+1) -3∫ x²/(x+1) dx
x³/(x+1) -3∫ (x²-1)/(x+1) +1/(x+1) dx
x³/(x+1) -3∫ (x-1) +1/(x+1) dx
x³/(x+1) -3(x²/2 - x + ln(x+1)) + C
6. If you let u=x+1, the problem is reduced to integrating a simple polnomial.

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 17, 2004
Today on TSR

### Life lessons uni will teach you

Questionable decision-making and constant surprises

### University open days

1. Loughborough University
Fri, 21 Sep '18
2. University of Cambridge
Fri, 21 Sep '18
3. Richmond, The American International University in London