In Exercise 61 in the section on Polynomial and Rational Functions, we gave the function defined by A(x) = 0.003631x³ - 0.03746x² + 0.1012x + 0.009 as the approximate blood alcohol concentration in a 170-lb woman x hours after drinking 2 oz of alcohol on an empty stomach, for x in the interval 30, 54.

(a) Approximate the change in alcohol level from 1 to 1.2 hours.
(b) Approximate the change in alcohol level from 3 to 3.2 hours.