If f(x) = min {x, x2, x3}, then

f(x) is everywhere differentiable f'(x) > 0 for x > 1 f(x) is not differentiable at three points but continuous for all $x \in R$ f(x) is not differentiable for two values of x.

f(x) is not differentiable at three points but continuous for all $x \in R$

It is evident from the graph of f(x) that it is continuous for all $x \in R$ and not differentiable at x = -1, 0, 1.