# Thread: Limit representing the derivative

1. ## Limit representing the derivative

This limit represents the derivative of some function $f$ at some number $a$. State this $a$ and $f$.

How would you go about doing this? I understand that
$

f'(a) = \lim_{x \to a} \frac{f(x) - f(a)}{x-a}
$

but, it doesn't seem to apply for this. any help is appreciated!

2. Originally Posted by cdlegendary
This limit represents the derivative of some function $f$ at some number $a$. State this $a$ and $f$.

How would you go about doing this? I understand that
$

f'(a) = \lim_{x \to a} \frac{f(x) - f(a)}{x-a}
$

but, it doesn't seem to apply for this. any help is appreciated!
Use this definition (which you should also have learned):

$f'(a) = \lim_{h \to 0} \frac{f(a + h) - f(a)}{h}$