Volume of a Solid
Picture and Computation
with(plots):
Warning, the name changecoords has been redefined
The Base
| > | Bottom:=plot([t,t^2-4,t=-2..3],thickness=3,labels=[x,y]): | 
| > | Top:=plot([t,t+2,t=-2..3],thickness=3,labels=[x,y]): | 
| > | display(Bottom,Top); | 
The Solid
| > | plot3d(4+x^2+2*y^2,x=-2..3,y=x^2-4..x+2,filled=true,axes=boxed,orientation=[145,45]); | 
Computing the Volume
| > | Int(Int(4+x^2+2*y^2,y=x^2-4..x+2),x=-2..3); | 
| > | value(%); | 
| > | evalf(%); | 
| > |