Question: Surface or contour plot of discontinuous function

Please, how do I use surface or contour to plot discontinous function?

z = f(x,y) := x-.8193318913*sin(x)*cos(x)/(cos(x)^2+sinh(y)^2)-(0.2931044702e-2*(0.7500000000e-3*x^2-0.7500000000e-3*y^2+0.1622336517e-1))*sin(x)*cos(x)/(((0.7500000000e-3*x^2-0.7500000000e-3*y^2+0.1622336517e-1)^2+0.2250000000e-5*x^2*y^2)*(cos(x)^2+sinh(y)^2))-0.4396567053e-5*x*y*sinh(y)*cosh(y)/(((0.7500000000e-3*x^2-0.7500000000e-3*y^2+0.1622336517e-1)^2+0.2250000000e-5*x^2*y^2)*(cos(x)^2+sinh(y)^2)):

Please Wait...