y′ = 2(x − 3)−^2 and ,
y′′ is positive when x < 3.(C) represents the rate of change of mass with respect to time; y is
directly proportional to x if y = kx.(B).(B)(D) As the water gets deeper, the depth increases more slowly. Hence, the
rate of change of depth decreases: .(C) The graph of f is shown in the figure above; f is defined and
continuous at all x, including x = 1. Since