Question

instantaneous rate of change with respect x at x=4
f(x)=x^2-7x

Answer 1

did you get to derivatives yet?

Answer 2

If you are talking about instantaneous rate it is most likely derivative.

Answer 3

take the derivative and evaluate at the given point.

Answer 4

if not you have to do this by hand
\[\lim_{x\to 4}\frac{x^2-7x+12}{x-4}\]

Answer 5

it is basically the same thing.

Answer 6

how did u get the 12?

Answer 7

\[f(4)=-12\]

Answer 8

\[\lim_{x \rightarrow 4}\frac{ f(x)-f(4) }{ x-4 }\]

Answer 9

change in y over the change in x gives ... what @getusel wrote

Answer 10

factor, cancel, replace \(x\) by 4

Answer 11

this is actually the fundamental definition of derivative.

Answer 12

i got -1

Answer 13

That's not correct, once you cancel out the x-4's, you are left with x-3. Sustitute 4 for x and you get your true answer.

Answer 14

1?

Answer 15

There you go. Good job!

Answer 16

yay. thanks! ;)