A quartic surface that looks like a rounded cube in its simplest form, but gets more funky as the variables a, b, and c get further away from zero (see: Tooth Surface). The equation for Goursat's Surface is as follows:

x4 + y4 + z4 + a(x2 + y2 + z2) + b(x2 + y2 + z2) + c = 0

Log in or register to write something here or to contact authors.