Question

find the derivative of x^3 at x=-2 algebraically, jot my memory, do you use f(x+h)-f(x)/h?

Answer 1

Unless you are deriving the various formulas, there is no reason to use the fundamental approach.
Use the exponent rule:

\[\frac{ d x^n}{dx}= n x^{n-1} \]

Answer 2

once you have found the derivative, replace x with -2 and evaluate it to answer the question

Answer 3

Use the power rule. Easiest rule in calculus to remember. By the way phi already stated it above.

Answer 4

ok thank you soo, x^3 using the power rule,
3x^2 is the derivative, then plugging in x=-2 gives us
3(-2)^2=12?

Answer 5

yes

Answer 6

thank you phi and pre cal, im in calc 1 and it can be confusing at times, I guess the power rule is a lifesaver, much thanks

Answer 7

use calculus notation
for example y prime
or f prime of x

Answer 8

ok like this right f'(x)

Answer 9

yes
f'(-2)=12