Biologists have found that the speed of blood in an artery is a function of the distance of the blood from the artery’s central axis. According to Poiseuille’s law,* the speed (in centimeters per second) of blood that is r centimeters from the central axis of an artery is given by the function S(r) = C(R² − r²), where C is a constant and R is the radius of the artery. Suppose that for a certain artery, C = 1.76 × 10⁵ and R = 1.2 × 10⁻² centimeters.

a. Compute the speed of the blood at the central axis of this artery.

b. Compute the speed of the blood midway between the artery’s wall and central axis.