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!

Integral Calculus - Trigonometric Substitution

  1. Jan 5, 2012 #1
    1. The problem statement, all variables and given/known data
    2
    ∫ dx / (x+1)√[2x(x+2)]
    1

    2. Relevant equations

    Let x = tan θ if √(a^2 + x^2)
    Where a = constant

    3. The attempt at a solution

    2
    ∫ dx / (x+1)√(2x)√(x+2)
    1

    2
    1/√2 ( ∫ dx / (√x)(x+1)[√(x+2)]
    1

    Now make all x in terms of √x so we can apply relevant equation ( applied also to constant )

    2
    1/√2 ( ∫ dx / (√x)((√x)^2+1)[√(√x+2)]
    1

    Now before i go on I want to ask if this is possible so I can apply the rule of the tangent in substitution?
     
  2. jcsd
  3. Jan 5, 2012 #2

    lanedance

    User Avatar
    Homework Helper

    how about noticing that
    [tex] 2x(x+2) = 2(x^2+2x) =2(x^2+2x+1-1) = 2((x+1)^2-1) [/tex]
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Integral Calculus - Trigonometric Substitution
  1. Integral substitution? (Replies: 3)

  2. Integral substituting (Replies: 4)

Loading...