Question

Find the derivative of f(x) = 5/x at x = -1.

Answer 1

by hand, or can you use the formula for the derivative of \(\frac{5}{x}\) ?

Answer 2

It doesnt matter

Answer 3

if you can use the formula it is easy
\[\frac{d}{dx}[\frac{1}{x}]=-\frac{1}{x^2}\] and so
\[\frac{d}{dx}[\frac{5}{x}]=-\frac{5}{x^2}\]

Answer 4

put \(x=-1\) and you get the answer

Answer 5

if you have to do it taking limits, it is a bit harder with the algebra

Answer 6

Oh, Thanks!

Answer 7

yw