Differentiability

Solve For C please.


@HarshalSolanki But , then why its not following rolle's theorem.

@YouKnowwhere for rolles theorem some conditions need to be satisfied and by rolles theorem we comment on the root of the f'(x)

@HarshalSolanki I am applying rolle's theorem of f'(x) . Tell me one thing , can any function give f'(c)=0 for any c under its domain without fullfilling conditions of rolle's.

@YouKnowwhere yes it can