Question: Pesticide suppose that the number of thousands of insects killed by two brands of pesticide is given by
f(x, y) = 10,000 - 6500e-0.01x - 3500e-0.02y
where x is the number of liters of brand 1 and y is the number of liters of brand 2. What is the rate of change of insect deaths with respect to the number of liters of brand 1 if 100 liters of each brand are currently being used? What does this mean?