Integraal van $$$4 x^{3}$$$

Bepaal $$$\int 4 x^{3}\, dx$$$.

Pas de constante-veelvoudregel $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$ toe met $$$c=4$$$ en $$$f{\left(x \right)} = x^{3}$$$:

$${\color{red}{\int{4 x^{3} d x}}} = {\color{red}{\left(4 \int{x^{3} d x}\right)}}$$

Pas de machtsregel $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$ toe met $$$n=3$$$:

$$4 {\color{red}{\int{x^{3} d x}}}=4 {\color{red}{\frac{x^{1 + 3}}{1 + 3}}}=4 {\color{red}{\left(\frac{x^{4}}{4}\right)}}$$

Dus,

$$\int{4 x^{3} d x} = x^{4}$$

Voeg de integratieconstante toe:

$$\int{4 x^{3} d x} = x^{4}+C$$

$$$\int 4 x^{3}\, dx = x^{4} + C$$$A