Question

Let f : R → R be a function defined by f(x) = max{x, x²}. Let S denote the set of all points in R, where f is not differentiable. Then : 

(1) {0, 1} 

(2) {0} 

(3) ϕ(an empty set) 

(4) {1}

Answer 1

Answer is (1) {0, 1} 

f(x) = max(x, x²)

Non-differentiable at x = 0, 1 

S = {0, 1}