Drag on the graph to rotate it.
The definitions of x(u,v), y(u,v),
and z(u,v) can use: the variables u and v; the operators +, −, *,
and /; the functions sin(x), cos(x), atan(x),
abs(x), exp(x), log(x), and pow(x,y); and
the constant pi. Note that the operator ** can probably be used to do exponentiation,
but that pow(x,y) can do the same thing. Angles are measured in radians. The scale determines the range of
coordinates that are in view. Coordinates in the range −scale to scale
should be visible. If axes are drawn, they extend from −scale to scale along
each coordinate axis. In the default view, the y-axis (green) points upward, the z-axis (blue) points out of the screen,
and the x-axis (red) points to the right.