Let λ x-2 y=μ be a tangent to the hyperbola a^2 x^2-y^2= b^2. Then ((λ)/a)^2-((μ)/b)^2 is equal to:

Let $\displaystyle \lambda x-2 y=\mu$ be a tangent to the hyperbola $\displaystyle \mathrm{a}^2 x^2-y^2=\mathrm{b}^2$. Then $\displaystyle \left(\frac{\lambda}{\mathrm{a}}\right)^2-\left(\frac{\mu}{\mathrm{b}}\right)^2$ is equal to :