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Homework Help: Misc integral

  1. Mar 23, 2010 #1
    [tex]
    \int \frac{x}{\sqrt{3-x^4}}dx
    [/tex]
    [tex]
    u=x^2
    [/tex]
    [tex]
    du=2xdx
    [/tex]
    [tex]
    \frac{1}{2}\int\frac{du}{\sqrt{3-u^2}}
    [/tex]
    [tex]
    u=\sqrt{3}sinT
    [/tex]
    [tex]
    du=\sqrt{3}cosTdT
    [/tex]
    [tex]
    \frac{1}{2}\int \frac{\sqrt{3}cosT}{\sqrt{3}cosT}dT

    [/tex]
    [tex]
    \frac{x}{2}+C
    [/tex]
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Mar 23, 2010 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    Not x/2+C. T/2+C.
     
  4. Mar 23, 2010 #3
    You need not do the second u-substitution. Use an integral table to solve it once you have done the first u-substitution. You can google 'integral table' to find one if you don't have one in your book.
     
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