Question

How do you find the f '(x) using the definition of derivative in: `f(x)=1/x`?

Answer 1

Try this:
`lim_(h->0)(1/(x+h)-1/x)/h=lim_(h->0)1/h((x-x-h)/((x+h)x))=lim_(h->0)1/h((-h)/((x+h)x))=`
Simplifying `h` and taking the limit:
`-1/x^2`