Half-cone and triangle.
http://vicapow.github.io/equation-plot-webgl/#sqrt(-(x*x)%2B(x*y)) http://vicapow.github.io/equation-plot-webgl/#sqrt(-(x*x)%2B(x*y))http://vicapow.github.io/equation-plot-webgl/#0.1*cos%286.28...
0.1cos(6.28x)tan(3.14y)