Find the zeroes of the quadratic polynomial $\displaystyle x^{2}-15$ and verify the relationship between the zeroes and the coefficients of the polynomial.

$\displaystyle \begin{array}{l}\text { Let } \mathrm{P}(\mathrm{x})=\mathrm{x}^{2}-15 \qquad=(\mathrm{x}-\sqrt{15})(\mathrm{x}+\sqrt{15}) \therefore \text { Zeroes of } \mathrm{P}(\mathrm{x}) \text { are }-\sqrt{15} \text { and } \sqrt{15} \text { Verification- } \text { Sum of zeroes }=-\sqrt{15}+\sqrt{15}=\frac{0}{1}=\frac{- \text { coefficient of } \mathrm{x}}{\text { coefficient of } \mathrm{x}^{2}} \text { Product of zeroes }=-\sqrt{15} \times \sqrt{15}=-15=\frac{-15}{1}=\frac{\text { costant term }}{\text { coefficient of } \mathrm{x}^{2}}\end{array}$