8-07 Construct one half of a torus so its cross-section consists of two intersecting circles

> restart;

> a:=3:b:=4:c:=sqrt(a^2+b^2):

> r:=c+a*cos(t):

> x:=r*cos(s):

> y:=r*sin(s):

> z:=a*sin(t):

> u:=solve(b*z=a*x,s):

> k:=plot3d([x,y,z],s=-u..u,t=0..2*Pi,scaling=constrained,grid=[50,100],color=red):

> with(plots):

> with(plottools):

> display(k);

> vrml(k,"c:/My documents/87124/08/8-07.wrl",background_color=white);

>