1.
Let f(x)={max(x,x2),x282x,2<x4f(x) = \begin{cases} \max(|x|, x^2), & |x| \le 2 \\ 8 - 2|x|, & 2 < |x| \le 4 \end{cases}. Let SS be the set of points in the interval (4,4)(-4, 4) at which ff is not differentiable. Then SS