Question

Find the derivative of f(x) = -9/x at x = 6.
MEDAL!

Answer 1

@radar

Answer 2

-9/6= -3/2

Answer 3

I apologize. I was thinking about the limit. First you need to find the derivative of the function.
\[f(x)=-9x^{-1}\]

Answer 4

gotcha

Answer 5

Once you find the derivative, plug in your x-value and you've got your answer.

Answer 6

is it 2/3?

Answer 7

What did you get for the derivative?

Answer 8

-3/2

Answer 9

The derivative should be a function itself.

Answer 10

so my answer was not correct?

Answer 11

No. Do you know how to find derivatives?

Answer 12

no

Answer 13

@mondona Guessing like that is very rude. We're here to help you understand and learn.

Answer 14

Well then how do you plan on doing this? Have you ever heard of the power rule?

Power Rule:

\[f(x)=x^{n}\]\[f \prime (x)=nx^{n-1}\]

Answer 15

I agree Kainui. He is probably just used to the rest of the people here who spoon feed answers. Not his fault for that.

Answer 16

So if \[g(x)=5x^{2}\]the derivative would be\[g \prime(x)=10x\]Do you see how I used the power rule here?

Answer 17

Ok first off i am a girl , but thanks(: . second of all you told me to plug in and that is what I did.

Answer 18

Him/her, it was a generic placeholder. No need to take offense. And I said to plug it into the derivative, not the original function.

Answer 19

This is for a calculus class, yes?

Answer 20

i got my answer, bye

Answer 21

good luck on your next test! ;)

Answer 22

thanks! I have an A in this class, and i have one test left! dont you look like an retrice (;

Answer 23

You don't know how to find a derivative in a calculus class...... And you have an A..... Hmmm

Answer 24

too bad it's not calculus ;* , nice try hunny

Answer 25

Urm... derivatives is calculus

Answer 26

again... it looks like you dont know everything

Answer 27

http://en.wikipedia.org/wiki/Derivative

And aren't you snarky. I just wanted to help you. Don't get all mad at me because I wouldn't give you the answer without you doing any work.