Question

Which of the following are true?
if f ‘(c) = 0, then f ’’(c) = 0 at x = c.
if f ‘(c) = 0, f ‘’(c) is not automatically zero, at x = c.
if f ‘(c) = 0, then f ’’(c) > 0 at x = c.
if f ‘(c) = 0, then f ’’(c) < 0 at x = c.

Answer 1

Do you have any thoughts?

Answer 2

I don' think that it is a

Answer 3

is it b?