$$$a^{x} \ln\left(a\right)$$$ の $$$x$$$ に関する積分

$$$\int a^{x} \ln\left(a\right)\, dx$$$ を求めよ。

定数倍の法則 $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$ を、$$$c=\ln{\left(a \right)}$$$ と $$$f{\left(x \right)} = a^{x}$$$ に対して適用する:

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

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

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

したがって、

$$\int{a^{x} \ln{\left(a \right)} d x} = a^{x}$$

積分定数を加える:

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

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