Double Integrals

We can iterate integrate calls. For example, suppose we wanted to calculate

\begin{displaymath}
\int\int \left(x^3 - 3xy\right) \mathrm{d}y \mathrm{d}x.
\end{displaymath}


\begin{maximasession}
f(x,y) := x^3 - 3*x*y;
integrate(integrate(f(x,y), y), x);...
... x); \\
\o2. {{x^4 y}\over{4}}-{{3 x^2 y^2}\over{4}} \\
\end{maximasession}

Maxima does not provide arbitrary constants of integration; the user must remember them. It is easy to do definite integration, for example, we could do

\begin{displaymath}
\int_0^1\int_{\sqrt{x}}^{2-x} \left(x^3 - 3xy\right) \mathrm{d}y \mathrm{d}x.
\end{displaymath}

with
\begin{maximasession}
integrate(integrate(f(x,y), y, x^1/2, 2 - x), x, 0, 1);
\m...
... y, x^1/2, 2 - x), x, 0, 1); \\
\o3. -{{173}\over{160}} \\
\end{maximasession}





G. Jay Kerns 2009-12-01