(C) The winning times are positive, decreasing, and concave upward.(D) , where represents the area of a trapezoid.(B) f ′(x) = 0 for x = 1 and f ′′(1) > 0.(A) Solution curves appear to represent odd functions with a horizontal
asymptote. In the figure in question 17, the curve in (B) of the question
has been superimposed on the slope field.(B) Note that(C) v is not differentiable at t = 3 or t = 5.