The demand for dog food, in pounds, is Q^D = 4 - 2P + (1/100)(1) where P is the price of dog food and I is income. Assume initially that P = 1 and I = 100.
(a) Using calculus calculate the price elasticity of demand for dog food.
(b) Using calculus calculate the income elasticity of demand for dog food.
(c) Is dog food normal or inferior? Briefly explain your answer.
(d) Is dog food a luxury good or a necessity? Briefly explain your answer.