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Section 9.6 Functions of More than One Variable
We can also define functions of multiple variables and use the notation the same way as one variable functions.
> g(x,y) := sin(x) - cos(y);
\begin{equation*}
\displaystyle g\, := \,( {x,y} )\mapsto \sin \left( x \right) -\cos \left( y \right)
\end{equation*}
This function may be evaluated at a point, given as an ordered pair:
\begin{equation*}
\displaystyle 1
\end{equation*}
An example of a function of more than one variable is the volume of a circular cylinder.
> cylindervol(r,h) := Pi*r^2*h;
\begin{equation*}
\displaystyle cylindervol\, := \,( {r,h} )\mapsto \pi\,{r}^{2}h
\end{equation*}
\begin{equation*}
\displaystyle 45\,\pi
\end{equation*}
