Let f(x)= 1/x , find derivative of f using the definition of derivative

Answer 1

The definition of a derivative is f '(x) = lim_h→0 [f(x + h) - f(x)] / h. If we plug in f(x) = 1/x, then f '(x) = lim_h→0 [1/(x + h) - 1/x] / h. Now you need to find a way to get rid of the h in the denominator. Let me know if you get stuck!