$$$- 5^{u}$$$ 的积分

求$$$\int \left(- 5^{u}\right)\, du$$$。

对 $$$c=-1$$$ 和 $$$f{\left(u \right)} = 5^{u}$$$ 应用常数倍法则 $$$\int c f{\left(u \right)}\, du = c \int f{\left(u \right)}\, du$$$：

$${\color{red}{\int{\left(- 5^{u}\right)d u}}} = {\color{red}{\left(- \int{5^{u} d u}\right)}}$$

Apply the exponential rule $$$\int{a^{u} d u} = \frac{a^{u}}{\ln{\left(a \right)}}$$$ with $$$a=5$$$:

$$- {\color{red}{\int{5^{u} d u}}} = - {\color{red}{\frac{5^{u}}{\ln{\left(5 \right)}}}}$$

因此，

$$\int{\left(- 5^{u}\right)d u} = - \frac{5^{u}}{\ln{\left(5 \right)}}$$

加上积分常数：

$$\int{\left(- 5^{u}\right)d u} = - \frac{5^{u}}{\ln{\left(5 \right)}}+C$$

$$$\int \left(- 5^{u}\right)\, du = - \frac{5^{u}}{\ln\left(5\right)} + C$$$A