A cup of coffee, cooling off in a room at temperature 23°C, has cooling constant k = 0.083 min ¹. (a) How fast is the coffee cooling (in degrees per minute) when its temperature is T = 71°C? Cooling at the rate = min (b) Use the Linear Approximation to estimate the change in temperature over the next 9s when T = 71°C. Estimated to cool = = °C over the next 9 s (c) The coffee is served at a temperature of 86°C. How long should wait before drinking it if the optimal temperature is 65°C? Waiting time = min you