9. Suppose that the demand equation for a certain commodity is g = 60 0.1p, for 0 S p S 600 , where q is the number of items and p is the price per item, in 15. a. Express the elasticity of demand as a mction of p . (E(p) = [](q')) 4 points 9 b. At what price is the revenue maximized? 4 points c. Determine the prices where revenue is decreasing and where revenue is increasing. 4 points