## Calculus: Early Transcendentals 8th Edition

(a) $T°C = 20°C-10h$ (b)$-30°C\leq T\leq 20°C$
As dry air moves upward, it expands and in doing so cools at a rate of about 1°C for each 100-m rise, up to about 12 km. (a) If the ground temperature is 20°C, then write a formula for the temperature at height h. The temperature at height $h$ km is $T°C = 20°C-10h$ Here, $0\leq h \leq 12$ (b) The range of temperature can be expected if a plane takes off and reaches a maximum height of 5 km. The temperature at height 5 km is $T°C = 20°C-10(5)°C=-30°C$ Here, range of the temperature is $-30°C\leq T\leq 20°C$