If $\mathrm{p}, \mathrm{q}, \mathrm{r}$ are in $\mathrm{GP}$ and the equations $\mathrm{px}^{2}+2 \mathrm{qx}+\mathrm{r}=0$ and $\mathrm{d} \mathrm{x}^{2}+2 \mathrm{ex}+\mathrm{f}=0$ have a common root, then show that
$\frac{\mathrm{d}}{\mathrm{p}}, \frac{\mathrm{e}}{\mathrm{q}}, \frac{\mathrm{f}}{\mathrm{r}}$ are in $\mathrm{AP}$