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$$$\sin{\left(x \right)} - \frac{1}{x}$$$ 的積分
您的輸入
求$$$\int \left(\sin{\left(x \right)} - \frac{1}{x}\right)\, dx$$$。
解答
逐項積分：
$${\color{red}{\int{\left(\sin{\left(x \right)} - \frac{1}{x}\right)d x}}} = {\color{red}{\left(- \int{\frac{1}{x} d x} + \int{\sin{\left(x \right)} d x}\right)}}$$
$$$\frac{1}{x}$$$ 的積分是 $$$\int{\frac{1}{x} d x} = \ln{\left(\left|{x}\right| \right)}$$$：
$$\int{\sin{\left(x \right)} d x} - {\color{red}{\int{\frac{1}{x} d x}}} = \int{\sin{\left(x \right)} d x} - {\color{red}{\ln{\left(\left|{x}\right| \right)}}}$$
正弦函數的積分為 $$$\int{\sin{\left(x \right)} d x} = - \cos{\left(x \right)}$$$：
$$- \ln{\left(\left|{x}\right| \right)} + {\color{red}{\int{\sin{\left(x \right)} d x}}} = - \ln{\left(\left|{x}\right| \right)} + {\color{red}{\left(- \cos{\left(x \right)}\right)}}$$
因此，
$$\int{\left(\sin{\left(x \right)} - \frac{1}{x}\right)d x} = - \ln{\left(\left|{x}\right| \right)} - \cos{\left(x \right)}$$
加上積分常數：
$$\int{\left(\sin{\left(x \right)} - \frac{1}{x}\right)d x} = - \ln{\left(\left|{x}\right| \right)} - \cos{\left(x \right)}+C$$
答案
$$$\int \left(\sin{\left(x \right)} - \frac{1}{x}\right)\, dx = \left(- \ln\left(\left|{x}\right|\right) - \cos{\left(x \right)}\right) + C$$$A