if \ C= \left|\begin{array}{ccc}(x+y)^{2}&x^{2} &1\\(z+x){2}&y^{2}&1\\(x+y)^{2}&z^{2}&1\end{array}\right|
\ then \ Prove \ that, C= -2(x+y+z)(y-z)(z-x)(x-y)