I have a (large) rational function of two variables. If Mathematica rates it rationally, there is the right answer. If Mathematica evaluates it on machine accuracy numbers, there is the wrong answer.
I want to use RegionPlot to draw where this feature is positive.
Unfortunately, this doesn't give a good answer because RegionPlot displays machine accuracy values of x and y by default. How do I force it to draw only rational values of x and y?