Chapter 4 - Slope

4.6 Minima & Maxima

A function f(x) with local positive slope implies an increasing function with x; a negative slope implies a decreasing function with x, and a zero slope implies a "locally flat" function.. Therefore, a zero slope implies either a minimum or a maximum (it might also implies an inflection point if the "slope" of the "slope-function" (second derivative) is zero as well). Finding the maxima and minima of functions can therefore be done in two steps: 
- first calculate the slope of the function 
- second solve for the zero of the slope-function.

This is illustrated in the following Maple worksheet using the Skewed Mexican function

f(x) = x 4 - 3 x 2 - x

which we used previously. The worksheet only uses Maple commands that we have seen previously, and should easily be followed.

 

The next worksheet does the same for the function

f(x) = sin(x) + cos(x)

in the domain -p to +p.


 
Section 4.5 Chapter 4 Exercises       TOC

  Any questions or suggestions should be directed to

   Michel Vallières at vallieres@drexel.edu