Integral of $$$\sqrt{2 - 3 x}$$$

Find $$$\int \sqrt{2 - 3 x}\, dx$$$.

Let $$$u=2 - 3 x$$$.

Then $$$du=\left(2 - 3 x\right)^{\prime }dx = - 3 dx$$$ (steps can be seen »), and we have that $$$dx = - \frac{du}{3}$$$.

So,

$${\color{red}{\int{\sqrt{2 - 3 x} d x}}} = {\color{red}{\int{\left(- \frac{\sqrt{u}}{3}\right)d u}}}$$

Apply the constant multiple rule $$$\int c f{\left(u \right)}\, du = c \int f{\left(u \right)}\, du$$$ with $$$c=- \frac{1}{3}$$$ and $$$f{\left(u \right)} = \sqrt{u}$$$:

$${\color{red}{\int{\left(- \frac{\sqrt{u}}{3}\right)d u}}} = {\color{red}{\left(- \frac{\int{\sqrt{u} d u}}{3}\right)}}$$

Apply the power rule $$$\int u^{n}\, du = \frac{u^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$ with $$$n=\frac{1}{2}$$$:

$$- \frac{{\color{red}{\int{\sqrt{u} d u}}}}{3}=- \frac{{\color{red}{\int{u^{\frac{1}{2}} d u}}}}{3}=- \frac{{\color{red}{\frac{u^{\frac{1}{2} + 1}}{\frac{1}{2} + 1}}}}{3}=- \frac{{\color{red}{\left(\frac{2 u^{\frac{3}{2}}}{3}\right)}}}{3}$$

Recall that $$$u=2 - 3 x$$$:

$$- \frac{2 {\color{red}{u}}^{\frac{3}{2}}}{9} = - \frac{2 {\color{red}{\left(2 - 3 x\right)}}^{\frac{3}{2}}}{9}$$

Therefore,

$$\int{\sqrt{2 - 3 x} d x} = - \frac{2 \left(2 - 3 x\right)^{\frac{3}{2}}}{9}$$

Add the constant of integration:

$$\int{\sqrt{2 - 3 x} d x} = - \frac{2 \left(2 - 3 x\right)^{\frac{3}{2}}}{9}+C$$

$$$\int \sqrt{2 - 3 x}\, dx = - \frac{2 \left(2 - 3 x\right)^{\frac{3}{2}}}{9} + C$$$A