(D) The graph of f ′(x) = x sin x − cos x is drawn here in the window [0,4]
× [−3,3]:
A local maximum exists at x = 0, where f ′ changes from positive to
negative; use your calculator to approximate a.
(C) f ′′ changes sign when f ′ changes from increasing to decreasing (or
vice versa). Again, use your calculator to approximate the x-coordinate at
b.
(E) Eliminating t yields the equation .
(B).
(A) Since if t = 2. We note that, as t
increases through 2, the sign of |v|′ changes from negative to positive,
assuring a minimum of |v| at t = 2. Evaluate |v| at t = 2.
