1. ## Derivative

Calculate the derivative of f(x) = 1/x using the method:

lim ( f(x + h) - f(x) ) / h.

Its been so long since I've calucated a derivative this way. Can someone go through the steps please. Thanks a lot

2. Originally Posted by jzellt
Calculate the derivative of f(x) = 1/x using the method:

lim ( f(x + h) - f(x) ) / h.

Its been so long since I've calucated a derivative this way. Can someone go through the steps please. Thanks a lot
$\frac{\frac{1}{x+h}-\frac{1}{x}}{h}=\frac{\frac{-h}{x(x+h)}}{h}=\frac{-1}{x(x+h)}$

$\lim_{h\to0}\frac{-1}{x(x+h)}=-\frac{1}{x^2}$