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Homework Help: Another chain rule: easy one

  1. Mar 13, 2008 #1
    [SOLVED] another chain rule: easy one

    [tex]y=xe^{-x^2}[/tex]

    i have no i dea how to start.
    [tex] f'= x^{x^2} or -2x^blah blah blah [/tex]

    just get me started and i'll promise you i will finish it myself
     
    Last edited: Mar 13, 2008
  2. jcsd
  3. Mar 13, 2008 #2
    This is actually an application of the product rule, then the chain rule.
     
  4. Mar 13, 2008 #3
    You will probably want to use the product rule and the rule for finding the derivative of [tex]e^{g(x)}[/tex]
     
  5. Mar 13, 2008 #4
    Product rule!!!

    [tex]f(x)=e^{-x^2}[/tex]

    derivative of e is itself, times the derivative of it's exponent.
     
  6. Mar 13, 2008 #5
    wow 3 replies all at 22:49 ... you just got the royal treatment :D
     
  7. Mar 13, 2008 #6
    ROFL:rofl:
     
  8. Mar 13, 2008 #7

    Dick

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    Start with the product rule. When you get to needing to find d/dx(e^(-x^2)) then remember the chain rule says (f(g(x)))'=f'(g(x))*g'(x). f is exp. g(x)=-x^2. So?
     
  9. Mar 13, 2008 #8
    Solved it
    thanks
     
  10. Mar 13, 2008 #9

    Dick

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    Geez. I'm really late.
     
  11. Mar 13, 2008 #10
    [tex] Y'= e^{-x2}(1-2x^{2})[/tex]
    thanks for the help
     
  12. Mar 13, 2008 #11
    Looks right^^
     
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