> 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):

> plot3d([x,y,z],s=-u..u,t=0..2*Pi,scaling=constrained,grid=[20,20],lightmodel=light3,title="87121 By J.S.C.");