> plot3d([cos(x)*cos(y), cos(x)*sin(y), sin(x)], x = 0 .. 2*Pi, y = 0 .. Pi); 1
 

Plot 

> plot3d([(1-t*sin(1/2*x))*cos(x), (1-t*sin(1/2*x))*sin(x), t*cos(1/2*x)], t = (-1)/2 .. 1/2, x = 0 .. 2*Pi); 1
plot3d([(1-t*sin(1/2*x))*cos(x), (1-t*sin(1/2*x))*sin(x), t*cos(1/2*x)], t = (-1)/2 .. 1/2, x = 0 .. 2*Pi); 1
 

Plot 

> plot3d([x+`*`(y, 0), x^2+y, x^3+y], x = -5 .. 5, y = -10 .. 10); 1
 

Plot 

>
 

>
 

>