The volume of this solid can be expressed as a double integral by subtracting a volume below g(x, y) from a volume below f(x, y) Volume = JJ dA D Where D = {(x, y)| Alternatively, we could calculate a triple integral: volume dV R Where R = {(x, y, z) | (x, y) ED,Consider the solid bounded by the two surfaces > - f(x, !) = 1ex and z = g(x, y) = a and the planes y = 1 and y = -1 0 .8 0.6 Z 0.4 0.2 0