Added features:[br]- can fix the line of optimization (Fix F)[br]- added the initial line of optimization (dotted line)[br]- for integral solutions, P lies on the integral solutions only[br][br]Modified from [url=https://www.geogebra.org/u/orchiming]Anthony OR 柯志明[/url]'s applet[br]https://www.geogebra.org/m/mWnK6uAH