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!

Integration help

  1. Mar 26, 2009 #1
    1. The problem statement, all variables and given/known data
    Integral of 1/(x^2+sqrt(x)) dx
    3. The attempt at a solution

    i tried u=sqrt(x)
    so then 2udu=dx
    u^2=x

    so then 2 integral u/(u^4+u) du

    then integral 2/(u^3+1)du then i factored it with sum of cubes then i did partial fraction's
    on it is this the right approach.
     
  2. jcsd
  3. Mar 26, 2009 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    Seems fine to me so far.
     
  4. Mar 26, 2009 #3
    but when i do the partial fractions after i factor the sum of cubes i get an unfactorable quadratic and i can't get the terms to cancel out with out the other cancilind out to find out the leading co-effiecients of the numertors of the partial fractions.
     
  5. Mar 26, 2009 #4

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    Yes, you do get an irreducible quadratic. Complete the square in the denominator and use a trig substitution.
     
  6. Mar 26, 2009 #5
    we havn't learned trig substitution yet.
     
  7. Mar 26, 2009 #6

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    I guess I don't see any other way to do it. There's an arctan in there I don't see how to get around.
     
  8. Mar 26, 2009 #7
    ok this wasn't a required problem my teacher said some of us could maybe do it
    so ill just wait till we learn trig sub.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Integration help
  1. Integral help (Replies: 4)

  2. Integration Help (Replies: 5)

  3. Integration help! (Replies: 3)

  4. Help with an integral (Replies: 1)

  5. Integrals help (Replies: 7)

Loading...