Let f: R → R be a function defined by f(x) = max {x, x3}, then-
f (x) is not differentiable at 3 points
f(x) is continuous at all points
f (x) is not differentiable at x = 0
y=x3
Clearly not differentiable at x= 0, ±1.
2nd method
Solvingx3= x, we have x= 0, ±1
∴ Max {x,x2}= x when x<-1
=x3 when -1 ≤ x ≤ 0
= x when 0 < x ≤ 1
=x3 when x < 1