Question

Find the derivative of f(x) = 2 divided by x at x = -2.

Answer 1

@zzr0ck3r

Answer 2

\(f(x) = \dfrac{2}{x}\)

Find \(f'(-2)\)

Answer 3

-1?

Answer 4

it is the same thing as \(f(x)=2\cdot x^{-1}\)

apply the power rule

Answer 5

So first find the derivative then plug in x = -2, you can use exponent rules to bring the x up so \[f(x)= 2 \times x^{-1}\]

Answer 6

is the answer -1?

Answer 7

Solomon beat me to it :P

Answer 8

No, -1 is not right

Answer 9

\(f(x) = 2x^{-1} \)

Use the power rule: for \(f(x) = n^n\), \(f'(x) = nx^{n - 1}\)

Answer 10

-1 is f(-2), but NOT f`(-2)

Answer 11

The 2 is just a constant.

Answer 12

You have to find the derivative first, what is the derivative of \[f(x) = \frac{ 2 }{ x }\]

Answer 13

As others have suggested, use the power rule mathstudent also shows the rule.

Answer 14

the rule here is:


\(\large\color{royalblue}{ \displaystyle \frac{ d }{dx}\left( {\rm a}\cdot x^{\rm n}\right) = {\rm a}\cdot\frac{ d }{dx}\left( x^{\rm n}\right)={\rm a}\cdot\left({\rm n}\cdot x^{{\rm n}-1}\right)={\rm an}\cdot x^{n-1}}\)

Answer 15

this is general (for all x except x=0)

Answer 16

now, in your case

\(\large\color{royalblue}{ \displaystyle \frac{ d }{dx}\left( {\rm 2}\cdot x^{\rm -1}\right) = ?}\)

Answer 17

basically, I take the constant out, differentiate the x^n part, and multiply the result from the derivative of x^n times the constant.

Answer 18

take a shot pliz

Answer 19

1/2

Answer 20

I don't think so

Answer 21

-1/2

Answer 22

1

Answer 23

yup, like that

Answer 24

-1/2

Answer 25

why did you say 1?

Answer 26

if you have any questions please ask whatever is troubling you.

Answer 27

thanks