If *f*(*x*) is a differentiable function, or differentiable except, say, at a
finite set of of points, we can try to find where it achieves
its minimum or maximum
value by looking at *f*'(*x*). When *f*'(*x*)>0 the function is
increasing. When *f*'(*x*)<0 the function is decreasing. When
*f*'(*x*)=0 or is undefined, we have a candidate for a local maximum or
minimum. We then have to examine the behavior of the function by
looking at its first and/or second derivatives to see if we have found
a global minimum or a global maximum or neither.

Wed Apr 21 08:17:28 EDT 1999