Use the definition of a derivitive to find f'(x).
Lim as h approaches 0 [f(x+h)-f(x)]/h
The Attempt at a Solution
I know that the answer is supposed to be -1/(1-4X)2 but I keep getting 4/(1-4X)2. This is what I have done so far (I hope this isn't too hard to understand):
*cancel the numerator values*
*divide by 1/h and let h=0*
What am I doing wrong?