When the air temperature is 20° F, the rate of change of the wind chill temperature t (°F) is given by dt / dw = - 4.352w-0.84 where w is wind speed in miles per hour.
(a) Will both the rate of change of wind chill temperature and wind chill temperature decrease as the windspeed increases? Explain.
(b) If the wind chill temperature is 1°F when the wind speed is 31 mph and the air temperature is 20°F, find the function that models the wind chill temperature.