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Homework Help: ((x^2)+1)^2 using substitution

  1. Jul 20, 2010 #1
    1. The problem statement, all variables and given/known data
    ((x^2)+1)^2 integrate using substitution


    2. Relevant equations



    3. The attempt at solution
    ok so i let u= x^2 + 1
    du/dx = 2x
    du= 2xdx
    where do i go from there
     
    Last edited: Jul 20, 2010
  2. jcsd
  3. Jul 20, 2010 #2

    Mark44

    Staff: Mentor

    Do what with ((x^2)+1)^2 using substitution?
     
  4. Jul 20, 2010 #3
    integrate using substitution, my bad forgot to put that down
     
  5. Jul 20, 2010 #4

    Mark44

    Staff: Mentor

    That's the reason for this: 1. The problem statement, all variables and given/known data

    So is this it?
    [tex]\int (x^2 + 1)^2 dx[/tex]

    I wouldn't use substitution for this one.
     
  6. Jul 20, 2010 #5
    I wouldn't either. I would expand and then solve but the question said to use substitution
     
  7. Jul 20, 2010 #6

    vela

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Education Advisor

    The substitution u=x2+1 won't help. What substitution does the form x2+1 suggest? Think trig functions.
     
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