设由方程$e^{xy}-xy^{2}=e^{2}$确定的函数为$y = y(x)$，求$\left.\dfrac{dy}{dx}\right|_{x = 0}$.

设$f(x)$在点$x = 1$处连续，且$\lim\limits_{x \to 1}f(x)=2$，则$f(1) =$（　　）.

$\lim\limits_{x \to +\infty}(\sqrt{x + 2}-\sqrt{x - 3})$.