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!

Tough derivative definition

  1. Jun 2, 2014 #1


    User Avatar
    Gold Member

    hey pf!

    can you help me with this $$\lim_{h \to 0} \frac{f(x+3h^2) - f(x-h^2)}{2h^2}$$

    i know the definition and have tried several substitutions, but no help. anyone have any ideas?
  2. jcsd
  3. Jun 2, 2014 #2


    User Avatar
    Gold Member

    nevermind, lopitals rule did the trick
  4. Jun 2, 2014 #3


    User Avatar
    Homework Helper

    hint 1
    hint 2
    $$\lim_{h \to 0} \frac{f(x+3h^2) - f(x-h^2)}{2h^2}=\lim_{h \to 0}\left[\frac{3}{2}\frac{\mathrm{f}(x+3h^2)-\mathrm{f}(x)}{3h^2}+\frac{1}{2}\frac{\mathrm{f}(x-h^2)-\mathrm{f}(x)}{-h^2}\right]$$
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Discussions: Tough derivative definition
  1. Tough derivative problem (Replies: 10)

  2. Derivative definition? (Replies: 1)