



 
Hi Meagan, Let me try a slightly different problem
The limit definition of the derivative is With my function the numerator of the limit fraction is Factor the numerator of this expression as a difference of cubes and simplify. You will find a factor of h. Now divide by h to obtain
Simplify. There is no longer an h in the denominator and you can see the result of taking the limit as h approaches zero. I hope this helps,  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 