1. Not finding help here? Sign up for a free 30min 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!

Integrals by parts im stuck

  1. Feb 1, 2006 #1

    u=lnt dv= t^.5 dt
    du=1/t dt v= (2t^1.5)/3

    i keep on getting stuck with this integral. any help would be appreciated
  2. jcsd
  3. Feb 1, 2006 #2
    i dont want anyone to wast their time with this, this hw is due exaclty 6 hours from now, so if you dont see this thread until 5 hours after i originally posted it, dont even worry about it
  4. Feb 1, 2006 #3


    User Avatar
    Staff Emeritus
    Science Advisor

    It won't take long enough to worry about wasting time:
    You already have [itex]\int_1^4 \sqrt{t}(ln(t))dt[/itex] and
    you have set u= ln t so [itex]du= \frac{1}{t}dt[/itex] and [itex]dv= t^{\frac{1}{2}}dt[/itex] so that [itex]v= \frac{2}{3}t^{\frac{3}{2}}[/itex].

    Okay, plugging that into the integration by parts formula gives
    [tex]\int_1^4\sqrt{t}(ln(t))dt= \frac{2}{3}t^{\frac{3}{2}}ln(t)\left|_1^4- \frac{2}{3}\int_1^4 t^{\frac{1}{2}}dt[/itex]

    Why would you have any difficulty with that?
  5. Feb 1, 2006 #4

    oooooo i forgot to transfer the 2/3 to the left. thank you very much kind sir

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Integrals by parts im stuck
  1. Im Stuck (Replies: 4)