Question

lim ((1/(x+h))-(1/x))/h
h->0

Answer 1

guess you are trying to find the derivative of
\[f(x)=\frac{1}{x}\] right?

Answer 2

ya

Answer 3

i know the answer is 1/x^2 but we need to use that formula and solve it

Answer 4

actually it is
\[-\frac{1}{x^2}\]

Answer 5

you just have to do the algebra
\[\frac{1}{x+h}-\frac{1}{x}=\frac{x-(x+h)}{x(x+h)}=\frac{-h}{x(x+h)}\]

Answer 6

now divide all this mess by h, so the h cancels in the numerator to give you
\[\frac{-1}{x(x+h)}\] and finally take the limit as h goes to zero and you are done

Answer 7

oh wow that was easy thank you

Answer 8

yw