# Proof involving limit of derivative

ptolema

## Homework Statement

give an example of a function f for which lim f(x) as x$$\rightarrow$$$$\infty$$ exists, but lim f'(x) as x$$\rightarrow$$$$\infty$$ does not exist.

## Homework Equations

f'(x) = lim [f(x+h)-f(x)]/h as h$$\rightarrow$$0

## The Attempt at a Solution

for some reason, i can only seem to find equations where lim f(x) as x$$\rightarrow$$$$\infty$$ does not exist, but lim f'(x) as x$$\rightarrow$$$$\infty$$ does exist. ex.f(x)=x and f'(x)=1

i.e. Let $f(x) = g(h(x))$. Then $f'(x) = g'(h(x)) \cdot h'(x)$.