$$$\frac{1}{a x}$$$ 关于$$$x$$$的积分

求$$$\int \frac{1}{a x}\, dx$$$。

对 $$$c=\frac{1}{a}$$$ 和 $$$f{\left(x \right)} = \frac{1}{x}$$$ 应用常数倍法则 $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$：

$${\color{red}{\int{\frac{1}{a x} d x}}} = {\color{red}{\frac{\int{\frac{1}{x} d x}}{a}}}$$

$$$\frac{1}{x}$$$ 的积分为 $$$\int{\frac{1}{x} d x} = \ln{\left(\left|{x}\right| \right)}$$$:

$$\frac{{\color{red}{\int{\frac{1}{x} d x}}}}{a} = \frac{{\color{red}{\ln{\left(\left|{x}\right| \right)}}}}{a}$$

因此，

$$\int{\frac{1}{a x} d x} = \frac{\ln{\left(\left|{x}\right| \right)}}{a}$$

加上积分常数：

$$\int{\frac{1}{a x} d x} = \frac{\ln{\left(\left|{x}\right| \right)}}{a}+C$$

$$$\int \frac{1}{a x}\, dx = \frac{\ln\left(\left|{x}\right|\right)}{a} + C$$$A