code for profit graph

> P1:=plot(1.5*x*1000-.0001*(x*1000)^2 - 2000,x=0..15,thickness=3):
P2:=plot( [[5,3625],[10,3625]], x=5..15,thickness=3,linestyle=3):
plots[display]({P1,P2},labels=[`Number of items in thousands`,`Profit`],labelfont=[TIMES,BOLD,18]);

>