Ecologists estimated that when population of a city is x thousand persons, the average level carbon monoxide in the air above the city will be L ppm(parts per million) where L=10+0.4x+0.0001x^2 . The population of the city is estimated to be x=752+23t+0.5t^2 thousand persons t years from the present.
a) Find the rate of change of carbon monoxide with respect to the population in the city
b) Find the rate of change of the population with respect to the time t.
c) Find the rate of change of carbon monoxide with respect to the time t.