#### Answer

a) $[-5,-4], [-2,0],[2,4].$
b) $[-4,-2], [0,2],[4,5].$
c)Never constant.

#### Work Step by Step

a) A function is increasing on an interval if for any $x_1\lt x_2$, $f(x_1)\leq f(x_2)$ for any $x_1,x_2$ in the interval. Thus here, according to the graph the function is increasing on $[-5,-4], [-2,0],[2,4].$
b) A function is decreasing on an interval if for any $x_1\lt x_2$, $f(x_1)\geq f(x_2)$ for any $x_1,x_2$ in the interval. Thus here, according to the graph the function is increasing on $[-4,-2], [0,2],[4,5].$
a) A function is constant on an interval if for any $x_1\lt x_2$, $f(x_1)= f(x_2)$ for any $x_1,x_2$ in the interval. Thus here, according to the graph the function is never constant.