Integral of $$$3^{x}$$$

Apply the exponential rule $$$\int{a^{x} d x} = \frac{a^{x}}{\ln{\left(a \right)}}$$$ with $$$a=3$$$:

$${\color{red}{\int{3^{x} d x}}} = {\color{red}{\frac{3^{x}}{\ln{\left(3 \right)}}}}$$

Therefore,

$$\int{3^{x} d x} = \frac{3^{x}}{\ln{\left(3 \right)}}$$

Add the constant of integration:

$$\int{3^{x} d x} = \frac{3^{x}}{\ln{\left(3 \right)}}+C$$

$$$\int 3^{x}\, dx = \frac{3^{x}}{\ln\left(3\right)} + C$$$A