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Homework Help: Maths Integration Problem! HELP

  1. Jun 19, 2007 #1
    Maths Integration Problem! HELP!!

    1. The problem statement, all variables and given/known data
    ok maths problems is like this:
    2.g. integrate (2x-1)/*square root x*

    3. The attempt at a solution

    ok. i split the equation up so that i am integrating 2x/*root x* - 1/*root x*

    the 1/root x integrates to - 2x^(1/2) and the constant is present (+c)

    but i cannot seem to integrate the (2x)/(x^(1/2))
    the answer is (4/3)x^(3/2)... but i cant seem to get it... even working backwards.
     
  2. jcsd
  3. Jun 19, 2007 #2
    Can you simplify [tex]\frac{x}{\sqrt{x}}[/tex] ?
     
  4. Jun 19, 2007 #3
    take the two out the front of the integral sign and then multiply?
     
  5. Jun 19, 2007 #4
    ok. i dont get where the x^(3/2) comes from.
    [tex]\frac{x}{\sqrt{x}}[/tex]
    becomes x.x^(-1/2)... then we add the powers?
    = x^(1/2)?
     
  6. Jun 19, 2007 #5
    Yes, correct. Can you integrate now?
     
  7. Jun 19, 2007 #6
    Yes, correct. Can you integrate now?
     
  8. Jun 19, 2007 #7
    x^(1/2) becomes (2/3)x^3/2) then multiplying in the two becomes....

    (4/3)x^(3/2) which is correct yeh?

    cool :D



    ok another one. (1-4x)/(x*root*x)... i cant do the (4x)/(x^(3/2))
     
  9. Jun 19, 2007 #8

    Gib Z

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    Homework Helper

    [tex] 4 \cdot \frac{x}{x^{1.5}}= 4 \cdot x^{-1/2}[/tex]
     
  10. Jun 19, 2007 #9
    damn it. lol. how stupid of me. missed the cancelling there totally. ah! no wonder i could do the rest of the chapter *shakes head*
     
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