1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Product rule error help

  1. Sep 8, 2008 #1
    y = ( 5 x-2 ) 3 / ( 2 x+5 ) 4

    I do it this way:

    f(x) = (5x-2)3
    g(x) = (2x+5)-4
    f'(x) = 3(5x-2)2
    g'(x) = -4(2x+5)-5

    By using the product rule:

    [3(5x-2)2](2x+5)-4 + (5x-2)3[-4(2x+5)-5]
    3(5x-2)2(2x+5)-4 -4(2x+5)-5(5x-2)3

    What's wrong with this answer?
     
  2. jcsd
  3. Sep 8, 2008 #2

    berkeman

    User Avatar

    Staff: Mentor

    Re: Differentiation

    Thread moved to Homework Help

    I do not believe you have differentiated correctly in these steps.
     
  4. Sep 8, 2008 #3
    Re: Differentiation

    Is it this way??

    f'(x) = 15(5x-2)2
    g'(x) = -8(2x+5)-5
     
    Last edited: Sep 8, 2008
  5. Sep 8, 2008 #4
    Re: Differentiation

    Yes, got it. Thanks for pointing out the error.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...