3 Blue 1 Brown has [url=https://www.youtube.com/watch?v=b7FxPsqfkOY]a sweet video[/url] about solving 2D equations (which also has a nice graphical explanation of solving 1 variable equations). [br][br]In this applet, the color is determined by the angle of the output with the origin, with the positive x-axis as red, and the point gets darker the larger the magnitude of the output.[br][br]So what do solutions of f(x,y)=0 look like?