Question

Calculus critical points question

Answer 1

I know how to do this. You find the derivative, and where it is equal to zero. However, on this questions, none of the answers are correct?

Answer 2

Yup, must be a typo in the function.

Answer 3

perhaps 24 instead of 42 ? :P
\(f(x) = 4x^3 -24x^2 +5\)

any option satisfying this f(x)

Answer 4

are you sure it's not C ?
I agree the critical points are at 0 and 7
f(0) = 5 is a max and f(7) = -681 in a min

Answer 5

hmm.. how are critical points 0 and 7 ?

Answer 6

Right, there is indeed an extremum at \(x=7\), but the choices' answers to part (a) say \(x=0\) and \(x=3\).

Answer 7

so the answer choices have a typo, not the question :)