Answer
a) There is one local minimum value which is $-1$ at $x=0$, and two local maximum local values which are $2$ and $1$ at $x=-2$ and $x=2$, respectively.
b) The intervals when the function is increasing are (-∞, -2) and (0,2).
The intervals when the function is decreasing are (-2,0) and (2, ∞)
Work Step by Step
a) The maximum local values are all that are at the top of crests that forms in functions (if any). While the minimum local values are all that are at the bottom of where U-shaped parts are formed (if any).
b) A function decreases when the slope is negative. While a function increases when the slope is positive.