Finding Critical Points and also a relative & absolute Minimum or Maximum is easily done using the
Calculus Made Easy APP at www.TiNspireApps.com . Simply select “Critical Points” in the Menu.
Here, you can either enter the given function f(x) in the top box or
enter its given derivative in the bottom box. We enter f(x) in below’s example.
Then, the derivative f'(x) is computed
and simplified to a more compact expression:
finding its zeros yields the following x values of the critical points.
Since we entered a periodic trigonometric function f(x)
we obtain infinitely many critical points of the format
shown below. Note that n87 represents a constant which
is usually denoted as K in textbooks.
Besides finding critical points, Maximum and Minimum values
you will also be able to find saddle points and inflection points under this menu option.