设 $y=y(x)$ 为微分方程满足初值问题 $\left\{\begin{array}{l}\left(1-x^2\right) y^{\prime \prime}-x y^{\prime}=0, \\ y(0)=0, y^{\prime}(0)=1\end{array}\right.$ 的解, 求极限 $\lim _{x \rightarrow \frac{\sqrt{2}}{2}} \frac{y^2(x)-\frac{\pi^2}{16}}{2 x^2-1}$.
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