Question

If geometric mean between x and y is G, then value of $\frac{1}{G^2-x^2}+\frac{1}{G^2-y^2}$ is equal to

• A. $G^2$
• B. $\frac{1}{G^2}$
• C. $2G^2$
• D. $\frac{3}{G^2}$

Answer 1

The correct option is B $\frac{1}{G^2}$

$\frac{1}{xy-x^2}+\frac{1}{xy-y^2}=\frac{1}{(x-y)}(-\frac{1}{x}+\frac{1}{y})=\frac{1}{xy}=\frac{1}{G^2}$