Which of the following best defines a critical point of a real-valued function ?

MATHEMATICS · Single correct · AP · Calculus AB · Analytical Applications of Differentiation · Analytical Applications of Differentiation

Problem

Which of the following best defines a critical point of a real-valued function

f

? (a) A real number

c

where

f'(c)=0

only. (b) A real number

c

in the domain of

f

where either

f'(c)=0

f'

does not exist. (c) A real number

c

where

f''(c)=0

. (d) A real number

c

where

f'(c)

does not exist but

f

is defined and differentiable elsewhere.