The value of \( \displaystyle \lim_{x \to 1} \frac{(x^2-1)\sin^2(\pi x)}{x^4-2x^3+2x-1} \) is equal to:
\( \frac{\pi^2}{6} \)
\( \frac{\pi^2}{3} \)
\( \frac{\pi^2}{2} \)
\( \pi^2 \)
