Ye i learnt that one the hard way. But ye u gotta prove itword. said:no.
f"(x) = 0 means theres a possible point of horizontal inflextion
you still have to check the gradient on both sides to verify that it is an inflexion
take f(x) = x4 for example
f"(0) = 0, but we know f(x) = x4 is a parabola
f'(-1) = -1, f'(0) = 0, f'(1) = 1 hence the shape \ _ / i.e. minimum
yeah, thats right, sorry bout that - Dont do what I did in an exam!word. said:no.
f"(x) = 0 means theres a possible point of horizontal inflextion
you still have to check the gradient on both sides to verify that it is an inflexion
take f(x) = x4 for example
f"(0) = 0, but we know f(x) = x4 is a parabola
f'(-1) = -1, f'(0) = 0, f'(1) = 1 hence the shape \ _ / i.e. minimum