Suppose that the manufacturer of a gas clothes dryer has found that when the unit price is p​ dollars, the revenue R​ (in dollars) is R(p)=-2p squared + 4000 p. ​(a) At what prices p is revenue​ zero? ​(b) For what range of prices will revenue exceed ​$800, 000 ​? ​(a) At what prices p is revenue​ zero? The revenue equals zero when p is ​$0 , 2000 . ​(Use a comma to separate​ answers, but do not use commas in any individual​ numbers.) ​(b) For what range of prices will revenue exceed ​$800, 000 ​? nothing