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 of a complicated radical function

  1. Dec 4, 2013 #1
    1. The problem statement, all variables and given/known data

    ∫(√x).[√(x+1)] dx

    2. Relevant equations



    3. The attempt at a solution

    Sorry but i couldn't get it any far than this u substitution


    u = √(x+1)
    du = [(1)/{2√(x+1)}]dx

    → dx = [2√(x+1)]du

    putting in the main expression


    ∫ √(u2 - 1). 2u2 du
     
  2. jcsd
  3. Dec 4, 2013 #2

    Mark44

    Staff: Mentor

    Here's a different approach. Combine the two radicals like so:
    ##\int \sqrt{x}\sqrt{x + 1}dx = \int \sqrt{x^2 + x}dx##

    Now, complete the square inside the radical to get √[(x + a)2 - b2]. At this point a trig substitution should work, assuming you have learned that technique.
     
  4. Dec 4, 2013 #3
    so that was mathematically valid : O to multiply..poor algebra me :(
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Integration of a complicated radical function
  1. A complicated integral (Replies: 1)

  2. Complicated integral (Replies: 2)

Loading...