Question

PLEASE HELP WILL GIVE A MEDAL
Find the derivative of f(x) = 4/x at x = 2.

Answer 1

@zepdrix

Answer 2

so replace x with 2
f(x) = 4/2 = 2

Answer 3

are we suppose to use the definition
or can use product or quotient rule?

Answer 4

or you know like the short cut rules

Answer 5

like I would just use power rule here

Answer 6

\[f(x)=4x^{-1} \\ f'(x)=4 \cdot ?\]

Answer 7

I will let you do the power rule thing :)

Answer 8

im confused how do I apply that?

Answer 9

if you have y=x^n then y'=nx^(n-1)

Answer 10

the n here is -1

Answer 11

so 4/2^2?

Answer 12

well almost

Answer 13

I think you forgot to bring down the -1

Answer 14

\[f(x)=4x^{-1} \\ f'(x)=4(-1)x^{-1-1}=-4x^{-2}=\frac{-4}{x^2} \]

Answer 15

ohhh so it would be -1?

Answer 16

the power is -1

Answer 17

so yeah n is -1

Answer 18

do you mind helping me with another one similar to this one?