text: # Derivative f(x)=x^3, f(a+h)-f(a)/h
  
  ## Homework Statement
  
  f(x)=x^3 f(a+h)-f(a)/h
  
  ## Homework Equations
  
  I am having troubles at the moment with the process, I am getting a^3+3a^2h+3ah^2+h^3-a^3.
  
  ## The Attempt at a Solution
  
  I have simplified the equation further and got 3a^2+3ah+h^2, help would be appreciated. Thanks for reading.
  
  You are trying to look for the derivative? Or just simplifying the equation?
  
  You will need to get the limit as h approaches 0 for derivative.
  
  You are trying to look for the derivative? Or just simplifying the equation?
  
  I already know the derivative, so just simplifying the equation.
  
  If you just need to simplify the equation f(a+h)-f(a)/h, then you have already done so by getting 3a^2+3ah+h^2 as the answer.
  
  If you just need to simplify the equation f(a+h)-f(a)/h, then you have already done so by getting 3a^2+3ah+h^2 as the answer.
  
  http://img192.imageshack.us/f/derivative.jpg/" [Broken] Can you check my math? Please.
  
  Last edited by a moderator:
  It should be fine.... According to my education system ><
  
  For me, i'll straight away use the definition of derivative
  f'(x) = limh->0 f(a+h)-f(a)/h
  
  Would not try to derive all the way from (f(b)-f(a))/(b-a), too time consuming.
  
  Ok, thank you.