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naspek
Dec15-09, 07:17 PM
integration of x / ((x+1)^4)
i cant use integration by subs..
partial fraction will consume time to answer this question..
which integration method should i use?

rock.freak667
Dec15-09, 07:20 PM
Try substitution instead, u=x+1

naspek
Dec15-09, 07:22 PM
Try substitution instead, u=x+1

ok.. when u = x + 1 ; du = 1 dx

i should get du = x dx first..
but subs method didnt work..

Tedjn
Dec15-09, 07:35 PM
Have faith, because it should work. If it still doesn't for you, post your work here.

phsopher
Dec15-09, 07:37 PM
You don't need to get du=xdx. rockfreak's suggestion works fine, just try it. Alternatively you could do a partial integration.

naspek
Dec15-09, 07:37 PM
got it!!!
(-1/2)(x+1)^-2 + (1/3)(x+1)^-3 + C.

what if i got x^2 / ((x+1)^4)

Tedjn
Dec15-09, 07:41 PM
The same trick works. You should try it.

naspek
Dec15-09, 08:07 PM
got it!! thanks guys!! =)