If $y=44 x^{45}+45 x^{-44}$, then $y^{\prime \prime}=$

If $y=e^{\sin ^{-1} x}$,then $\left(1-x^2\right) y_2-x y_1=$

If $f: R \rightarrow R$ is an even function which is twice differentiable on $R$ and $f^{\prime \prime}(\pi)=1$, then $f^{\prime \prime}(-\pi)$ is equal to

If $x^2 + y^2 + \sin y = 4$,then the value of $\frac{d^2y}{dx^2}$ at the point $(-2, 0)$ is

If $y = x^3 \log(\log_e(1 + x))$,then $y''(0)$ equals

If $\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1$,then $\frac{d^2 y}{d x^2}$ is