A cup of coffee cools according to a temperature function

MATHEMATICS · Single correct · AP · Calculus AB · Contextual Applications of Differentiation · Contextual Applications of Differentiation

Problem

T(t)

, measured in degrees Celsius, where

t

is the number of minutes after brewing. At

t = 8

, the derivative satisfies

T'(8) = -1.2

(units °C/min). Which of the following best interprets this value? (a) At 8 minutes, the coffee’s temperature is increasing at approximately

1.2\,^{\circ}\text{C}

per minute. (b) At 8 minutes, the coffee’s temperature is decreasing at approximately

1.2\,^{\circ}\text{C}

per minute. (c) At 8 minutes, the coffee’s temperature is decreasing at approximately

1.2

minutes per degree Celsius. (d) At 8 minutes, the coffee’s temperature is

1.2\,^{\circ}\text{C}