Integral of $$$a_{n} i_{n} + b_{n} i_{n} + 1$$$ with respect to $$$x$$$

Find $$$\int \left(a_{n} i_{n} + b_{n} i_{n} + 1\right)\, dx$$$.

Apply the constant rule $$$\int c\, dx = c x$$$ with $$$c=a_{n} i_{n} + b_{n} i_{n} + 1$$$:

$${\color{red}{\int{\left(a_{n} i_{n} + b_{n} i_{n} + 1\right)d x}}} = {\color{red}{x \left(a_{n} i_{n} + b_{n} i_{n} + 1\right)}}$$

Therefore,

$$\int{\left(a_{n} i_{n} + b_{n} i_{n} + 1\right)d x} = x \left(a_{n} i_{n} + b_{n} i_{n} + 1\right)$$

Add the constant of integration:

$$\int{\left(a_{n} i_{n} + b_{n} i_{n} + 1\right)d x} = x \left(a_{n} i_{n} + b_{n} i_{n} + 1\right)+C$$

$$$\int \left(a_{n} i_{n} + b_{n} i_{n} + 1\right)\, dx = x \left(a_{n} i_{n} + b_{n} i_{n} + 1\right) + C$$$A