MATHEMATICS · Single correct · AP · Calculus AB · Analytical Applications of Differentiation · Analytical Applications of Differentiation
Problem
For a continuous function f, the derivative satisfies f′(x)>0 for x<2, f′(2)=0, and f′(x)<0 for x>2. Which of the following best describes the behavior of f at x=2?
(a) f has a point of inflection at x=2 because the sign of f′(x) changes there.
(b) f has a local minimum at x=2 because the sign of f′(x) changes from positive to negative.
(c) f has a local maximum at x=2 because the sign of f′(x) changes from positive to negative.
(d) The information is insufficient to determine whether f has a local extremum at x=2.