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!

Finding the derivative of g(x)

  1. Mar 28, 2012 #1
    1. The problem statement, all variables and given/known data

    Let f(x) be a continuous and differentiable function on the interval 0 ≤ x ≤ 1, and let g(x)=f(3x). The table below gives values of f'(x), the derivative of f(x). What is the value of g'(0.1)?

    http://img845.imageshack.us/img845/442/33806538.jpg [Broken]


    2. Relevant equations



    3. The attempt at a solution

    g(0.1) = f(3(0.1))
    g(0.1) = f(0.3)
    g'(0.1) = f'(0.3)
    g'(0.1) = 1.096

    Did I do the problem correctly? Thanks!
     
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Mar 28, 2012 #2
    Look correct assuming the picture and problems statement are what you have shown.
     
  4. Mar 28, 2012 #3
    I think the answer should be E. g'(x) = 3*f'(3x). So, g'(0.1)=3*f'(0.3)=3*1.096=3.288
     
  5. Mar 28, 2012 #4
    ^ Actually that's correct because of the chain rule (haven't taken calculus in 5 years lol)

    g(x) = f(u), where u = 3x so
    g'(x) = f'(u)du = f'(3x)*3
     
  6. Mar 28, 2012 #5


    Thank you guys!
    Forgot to use chain rule, thought I could just multiply 3*(0.3)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Finding the derivative of g(x)
Loading...