Question: the graph of f ′(x) is continuous, positive, the graph of f ′(x) is continuous, positive, and has a relative maximum at x = 0. which of the following statements must be true?
a. the graph of f is always concave down.
b. the graph of f is always increasing.
c. the graph of f has a relative maximum at x = 0.
d. the graph of f has a relative minimum at x = 0.