Approximate the fundamental frequency of a rectangular membrane supported along all the edges by using Rayleigh's method with

\[W(x, y)=c_{1} x y(x-a)(y-b)\]

\[V=\frac{P}{2} \iint\left[\left(\frac{\partial w}{\partial x}\right)^{2}+\left(\frac{\partial w}{\partial y}\right)^{2}\right] d x d y \quad \text { and } \quad T=\frac{ho}{2} \iint\left(\frac{\partial w}{\partial t}\right)^{2} d x d y\]