Expanding oscillations can result from improperly tuned feedback systems. Suppose that a thermostat is supposed to keep a room at 20 C. You come in one morning and find the temperature is 21 C. To correct this you move the thermostat down by 1 C to 19 C. But, the next day the temperature has dropped to 19.5 C. (a) Suppose the temperature produced is a linear function on the thermometer. Find this function.