$$$- 14 x + \sin{\left(x \right)}$$$ 的积分

求$$$\int \left(- 14 x + \sin{\left(x \right)}\right)\, dx$$$。

逐项积分：

$${\color{red}{\int{\left(- 14 x + \sin{\left(x \right)}\right)d x}}} = {\color{red}{\left(- \int{14 x d x} + \int{\sin{\left(x \right)} d x}\right)}}$$

对 $$$c=14$$$ 和 $$$f{\left(x \right)} = x$$$ 应用常数倍法则 $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$：

$$\int{\sin{\left(x \right)} d x} - {\color{red}{\int{14 x d x}}} = \int{\sin{\left(x \right)} d x} - {\color{red}{\left(14 \int{x d x}\right)}}$$

应用幂法则 $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$，其中 $$$n=1$$$：

$$\int{\sin{\left(x \right)} d x} - 14 {\color{red}{\int{x d x}}}=\int{\sin{\left(x \right)} d x} - 14 {\color{red}{\frac{x^{1 + 1}}{1 + 1}}}=\int{\sin{\left(x \right)} d x} - 14 {\color{red}{\left(\frac{x^{2}}{2}\right)}}$$

正弦函数的积分为 $$$\int{\sin{\left(x \right)} d x} = - \cos{\left(x \right)}$$$:

$$- 7 x^{2} + {\color{red}{\int{\sin{\left(x \right)} d x}}} = - 7 x^{2} + {\color{red}{\left(- \cos{\left(x \right)}\right)}}$$

因此，

$$\int{\left(- 14 x + \sin{\left(x \right)}\right)d x} = - 7 x^{2} - \cos{\left(x \right)}$$

加上积分常数：

$$\int{\left(- 14 x + \sin{\left(x \right)}\right)d x} = - 7 x^{2} - \cos{\left(x \right)}+C$$

$$$\int \left(- 14 x + \sin{\left(x \right)}\right)\, dx = \left(- 7 x^{2} - \cos{\left(x \right)}\right) + C$$$A