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Partial derivative check me

  1. Apr 23, 2008 #1
    [SOLVED] Partial derivative ... check me plz

    [tex]f(x,y)=\sqrt[5]{x^7y^4}[/tex]

    [tex]f_x(x,y)=\frac 1 5(x^7y^4)^{-\frac{4}{5}}(7x^6y^4)[/tex]

    [tex]f_x(x,y)=\frac{7x^6y^4}{5\sqrt[5]{x^7y^4}}[/tex]

    Correct?
     
    Last edited: Apr 23, 2008
  2. jcsd
  3. Apr 23, 2008 #2

    Hootenanny

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    I don't think so.

    HINT:

    [tex]f(x,y) = x^{7/5}y^{4/5}[/tex]
     
  4. Apr 23, 2008 #3
    omg ... I'm embarassed :D

    ok so ...

    [tex]f_x(x,y)=\frac 7 5x^{\frac 2 5}y^{\frac 4 5}[/tex]
     
  5. Apr 23, 2008 #4

    Hootenanny

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    Sounds good to me :approve:
     
  6. Apr 23, 2008 #5
    Thanks Hootenanny :)
     
  7. Apr 23, 2008 #6

    Hootenanny

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    A pleasure as always roco :smile:
     
  8. Apr 23, 2008 #7

    Vid

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    You would have gotten the same answer, but the denominator has the wrong exponent.
     
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