Find any relative extrema of the function

This function is defined on and is differentiable on Its derivative is  

The derivative doesn't exist at It is zero where   so at  It is an even function and it is obviously increases for positive x and decreases for negative x. Hence it is positive on and negative on  and the function increases and decreases respectively.

This way we can determine the maximum and minimum of   is a local (one-sided) minimum, is a local one-sided maximum, is the local maximum and is a local minimum.