# Prove that the following functions do not have maxima or minima: $(i)\: f (x) = e^x$

This is first part of multipart q4

Toolbox:
• $\large\frac{d}{dx}(e^x)=e^x$
$f(x)=e^x$
On differentiating with respect to x we get
$f'(x)=e^x$
For maxima and minima $f'(x)=0$
$\Rightarrow e^x=0$
Which is not defined for any finite value.
Hence $f(x)=e^x$ does not have maxima and minima.

edited Aug 30, 2013