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Homework Help: Find derivative of function?

  1. Nov 12, 2008 #1
    1. The problem statement, all variables and given/known data

    Find derivative of function?
    if f(x) = (x^2 + 3x -2 ) (x^3-4)
    Find f`(x)

    2. Relevant equations

    FOIL or Multiply both

    3. The attempt at a solution

    I get
    5x^4 + 12x^3 - 6x^2 -8x-12

    is this right?
     
  2. jcsd
  3. Nov 12, 2008 #2

    Dick

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    Science Advisor
    Homework Helper

    Yes, it's correct. Why do you think it might not be??
     
  4. Nov 13, 2008 #3
    just checking
     
  5. Nov 13, 2008 #4
    I'd use the product rule.
     
  6. Nov 14, 2008 #5
    yes i believe it is.
     
  7. Nov 14, 2008 #6

    HallsofIvy

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    Science Advisor

    You could check by using the product rule as ducnguyen2000 suggested:
    the derivative of f(x) = (x^2 + 3x -2 ) (x^3-4) is (x^2+ 3x- 2)'(x^3- 4)+ (x^2+ 3x- 2)(x^3- 4)'.
     
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