x + h - V
Evaluate : lim
h→0
h
Answers
Answer:
Step-by-step explanation:
Also known as: (Definition of Limit), and (Increment definition of derivative)
f ’(x) = lim f(x+h) – f(x)
h→0 h
This equation is essentially the old slope equation for a line:
2 1
2 1
x x
y y m −
− =
f (x+h) – represents (y2)
f (x) – represents (y1)
x – represents (x1)
x + h − represents (x2)
h – represents the change in x or (x2 – x1) or ∆x
f (x+h) – f (x) – represents (y2 – y1)
Lim – represents the slope M as h→0
2 1
2 1
x x
y y M −
− = x h x
f x h f x
+ −
+ − = ( )
( ) ( )
h
f (x + h) − f (x) =
As ‘h’ gets smaller, the value of (x+h) gets closer to (x) and thus f(x+h) gets closer to f(x), and the slope of
the secant line gets closer to the slope of the tangent line at (x). And so as h→0, we get the limit of the
equation at (x)
f(x+h)
f(x)
x x+h
h
f(x) = 2(x – 4)
2