Using properties of determinants,show that $P\alpha^2+2q\alpha+r=0$,given that :p,q and r are not in G.P and $\begin{vmatrix}1 & \large\frac{q}{p} & \alpha+\large\frac{q}{p}\\1 & \large\frac{r}{q} & \alpha+\large\frac{r}{q}\\p\alpha+q &q\alpha+r &0\end{vmatrix}=0$.