Consider the following partial differential equation:

$\frac{de{l}^{2}u}{del{x}^2}+\frac{de{l}^{2}u}{del{y}^2}=0$

$u(0,y)=u(,y)=u(x,)=0,u(x,0)0$ with boundary conditions

$u(0,y)=u(,y)=u(x,)=0,u(x,0)$

Here you need $to$ use the separation $of$ variables method. Write down most $of$ your steps!