填空题 函数$$y = \ln(1 + x)$$的定义域是__________

填空题 函数$$y = \frac{\sqrt{4 - x}}{x - 3}$$的定义域是__________

填空题 $$\lim\limits_{x \to \infty}(1 + \frac{2}{x})^{2x} = $$__________，$$\lim\limits_{x \to \infty}(1 + \frac{1}{x})^{3x} = $$__________

填空题 函数$$y = \ln(1 + \sqrt{x})$$是由__________函数复合而成.【缺少答案，请补充】

填空题 函数$$y = \arctan(1 + x^2)$$是由__________函数复合而成.

填空题 $$\lim\limits_{x \to 0}\frac{\sin x}{3x} = $$__________，$$\lim\limits_{x \to 0}(1 + x)^{\frac{1}{x}} = $$__________.【缺少答案，请补充】

填空题 函数$$y = \ln\frac{x - 1}{x + 1}$$的定义域为__________

填空题 $$\lim\limits_{x \to 0}\frac{3x}{\sin x} = $$__________，$$\lim\limits_{x \to 0}\frac{\tan x}{2x} = $$__________.