Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Numerical differentiation using forward, backward and central finite difference

  1. Feb 2, 2010 #1
    ive been given this question for a uni assignment:

    given the function:

    f (x) = 5(x^1.3) +1.5(7x − 3)+ 3(e^− x) + ln(2.5(x^3))

    find the first derivative at all possible points within the interval [0, 6], with step length h = 1 for:
    forward difference aproximation, backward difference aproximation and central finite difference aproximation.

    having a bit of trouble with the question... pretty sure i know how to do most of it but not sure what to do when x=0 because ln(0) is undefined or -infinity...

    any ideas?

  2. jcsd
  3. Feb 2, 2010 #2
    Well, it says "for all possible points" which would exclude any points where ln(0) appears.
  4. Feb 8, 2010 #3

    LOL I'm guessing you're from brunel :P
    I've figured out how to do the hand calculations but not the matlab part
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook