If tan θ = \( \frac{12}{13} \), then find the value of \(\frac{2\sin\theta\cos\theta}{\cos^2\theta-\sin^2\theta}\).
\( \frac{13}{12} \)
\( \frac{413}{25} \)
\( \frac{312}{25} \)
\( \frac{512}{25} \)
If x = asinθ, and y = btanθ, then find the value of \(\frac{a^2}{x^2}-\frac{b^2}{y^2}\).