Volume Solid of Revolution (Donut) Shell
For the classes of Atul Roy
MATLAB code for creating the graph is below
syms u v
fsurf((cos(u)*2-4)*cos(v)+4,sin(u)*2,(cos(u)*2-4)*(-sin(v)),[0 2*pi 0 2*pi])
axis equal % x^2+y^2=4 revolved around x=4
hold on
syms t
fplot3(4+0*t,t,0*t,[-5 5])