- #1
terryds
- 392
- 13
Homework Statement
##f(x)=12x^2-5##
The value of ##\lim_{h\rightarrow 0}\frac{f(x+2h)-f(x-3h)}{6h}## is ...
A. 8x
B. 10x
C. 12x
D.18x
E. 24x
Homework Equations
##f'(x) = \lim_{h->0}\frac{f(x+h)-f(x))}{h}##
The Attempt at a Solution
[/B]
Looking at the problem question, it seems that it's kinda like the definition of derivative
But, it's different.
This is my attempt.
##\lim_{h\rightarrow 0}\frac{f(x+2h)-f(x)}{2h}*\frac{2h}{6h}-\frac{f(x-3h)-f(x)}{3h}*\frac{3h}{6h}##
##= f'(x) * 1/3 - f'(x) * 1/2##
##= f'(x)*(-1/6)##
##= 24x (-1/6)##
##= -4x##
But, it's not in the options. Please help