1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Integration (iii)

  1. Dec 15, 2009 #1
    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?
     
  2. jcsd
  3. Dec 15, 2009 #2

    rock.freak667

    User Avatar
    Homework Helper

    Try substitution instead, u=x+1
     
  4. Dec 15, 2009 #3
    ok.. when u = x + 1 ; du = 1 dx

    i should get du = x dx first..
    but subs method didnt work..
     
  5. Dec 15, 2009 #4
    Have faith, because it should work. If it still doesn't for you, post your work here.
     
  6. Dec 15, 2009 #5
    You don't need to get du=xdx. rockfreak's suggestion works fine, just try it. Alternatively you could do a partial integration.
     
  7. Dec 15, 2009 #6
    got it!!!
    (-1/2)(x+1)^-2 + (1/3)(x+1)^-3 + C.

    what if i got x^2 / ((x+1)^4)
     
  8. Dec 15, 2009 #7
    The same trick works. You should try it.
     
  9. Dec 15, 2009 #8
    got it!! thanks guys!! =)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook