precal
posted by Anonymous .
Spider Industries is a U.S.based company that testmarketed an electronic cobweb destroyer in Japan. The company's revenue, R, is a function of the number of destroyers sold, x, using the following formula R = 160x 0.2x^2.
If the company sold their destroyers for $180 each, what is the maximum revenue Spider Industries could bring in?
I thought it was $32,000 but that was incorrect.

Well, the equation is a parabola.The roots are x=0 and x=800 check that.
So the maximum must be at x=400
R=x(160.2x)=400*(160.2*400)=160*80
= you do it.