Model and solve constrained optimisation problems
Two non-negative dimensions add to \(18\,\mathrm{m}\). The product of the dimensions must be maximised
Let \(w\) be the first length and \(l\) the second length
\[w+l=18\]
\[A(w,l)=wl\]
The practical domain is \(w\in\left[0,18\right]\)
Use the practical domain and the derivative to obtain the answer