Extremum graphing question

[lrdheat]

On a graph of abs(cos X), is there a way for the graphing app function analysis to recognize minimum extremums? The app only recognizes maximums...seems to have difficulty with such a function defined at all X values that have a clear minimum f(X), but no defined f'(X) at those points.

Is it possible for the graphing app to be designed to find these extremums?

[lrdheat]

In graph app for abs(cos X), root does succeed where extremum fails in finding a value approximating a root (and labels it as an extremum!), but even this would fail if, instead, the function was abs(cos X) + 1.

Could the graphing app be designed to have success with these sorts of functions?

[cyrille de brébisson]

Hello,

The failure is due to the fact that the calculator derivates and then tries to find a 0 of the derivative to find extremums. Since the derivative of abs is not defined in 0, it fails to find the 0.

Cyrille

[Jan_D]

The Advanced Graphing app finds the minima.
In Numeric View choose: Trace – PoI –Vertical Extrema.

It finds a minimum function value of 1.52655665886E-16, but it could be worse!