Integraal van $$$\frac{\left(y - 4\right)^{2}}{3}$$$

Bepaal $$$\int \frac{\left(y - 4\right)^{2}}{3}\, dy$$$.

Pas de constante-veelvoudregel $$$\int c f{\left(y \right)}\, dy = c \int f{\left(y \right)}\, dy$$$ toe met $$$c=\frac{1}{3}$$$ en $$$f{\left(y \right)} = \left(y - 4\right)^{2}$$$:

$${\color{red}{\int{\frac{\left(y - 4\right)^{2}}{3} d y}}} = {\color{red}{\left(\frac{\int{\left(y - 4\right)^{2} d y}}{3}\right)}}$$

Zij $$$u=y - 4$$$.

Dan $$$du=\left(y - 4\right)^{\prime }dy = 1 dy$$$ (de stappen zijn te zien »), en dan geldt dat $$$dy = du$$$.

Dus,

$$\frac{{\color{red}{\int{\left(y - 4\right)^{2} d y}}}}{3} = \frac{{\color{red}{\int{u^{2} d u}}}}{3}$$

Pas de machtsregel $$$\int u^{n}\, du = \frac{u^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$ toe met $$$n=2$$$:

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

We herinneren eraan dat $$$u=y - 4$$$:

$$\frac{{\color{red}{u}}^{3}}{9} = \frac{{\color{red}{\left(y - 4\right)}}^{3}}{9}$$

Dus,

$$\int{\frac{\left(y - 4\right)^{2}}{3} d y} = \frac{\left(y - 4\right)^{3}}{9}$$

Voeg de integratieconstante toe:

$$\int{\frac{\left(y - 4\right)^{2}}{3} d y} = \frac{\left(y - 4\right)^{3}}{9}+C$$

$$$\int \frac{\left(y - 4\right)^{2}}{3}\, dy = \frac{\left(y - 4\right)^{3}}{9} + C$$$A