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: Chain rule

  1. Nov 17, 2005 #1
    I'm a little confused as to when to stop taking the derivative of the inside function when using the chain rule...

    Lets say I have f( g(x^2) )

    Would this be correct?
    f`( g(x^2) ) * g`(x^2) * 2x ?

    Or do I keep on going until the x is completely gone from the equation?
  2. jcsd
  3. Nov 17, 2005 #2
    nope, you're done. The idea here is that you only differentiate the functions given. You can't assume that there are still more. All this is is a double composite. It could have been written as F(g(h(x)), which is the same as before except with replcing th x^2 with h(x). Just do the setup and don't second guess yourself.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook