Suppose that the function f {\displaystyle f} is differentiable for all x {\displaystyle x} and that f ( − 1 ) = − 1 {\displaystyle f(-1)=-1} and f ( 2 ) = 5 {\displaystyle f(2)=5} .
(b) Suppose also that f ″ < 0 {\displaystyle f''<0} everywhere. Is it possible that f ′ ( 2 ) = 3 {\displaystyle f'(2)=3} ? Explain why or why not.
