Integral de $$$x^{2} - 7 x$$$

Halla $$$\int \left(x^{2} - 7 x\right)\, dx$$$.

Integra término a término:

$${\color{red}{\int{\left(x^{2} - 7 x\right)d x}}} = {\color{red}{\left(- \int{7 x d x} + \int{x^{2} d x}\right)}}$$

Aplica la regla de la potencia $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$ con $$$n=2$$$:

$$- \int{7 x d x} + {\color{red}{\int{x^{2} d x}}}=- \int{7 x d x} + {\color{red}{\frac{x^{1 + 2}}{1 + 2}}}=- \int{7 x d x} + {\color{red}{\left(\frac{x^{3}}{3}\right)}}$$

Aplica la regla del factor constante $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$ con $$$c=7$$$ y $$$f{\left(x \right)} = x$$$:

$$\frac{x^{3}}{3} - {\color{red}{\int{7 x d x}}} = \frac{x^{3}}{3} - {\color{red}{\left(7 \int{x d x}\right)}}$$

Aplica la regla de la potencia $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$ con $$$n=1$$$:

$$\frac{x^{3}}{3} - 7 {\color{red}{\int{x d x}}}=\frac{x^{3}}{3} - 7 {\color{red}{\frac{x^{1 + 1}}{1 + 1}}}=\frac{x^{3}}{3} - 7 {\color{red}{\left(\frac{x^{2}}{2}\right)}}$$

Por lo tanto,

$$\int{\left(x^{2} - 7 x\right)d x} = \frac{x^{3}}{3} - \frac{7 x^{2}}{2}$$

Simplificar:

$$\int{\left(x^{2} - 7 x\right)d x} = \frac{x^{2} \left(2 x - 21\right)}{6}$$

Añade la constante de integración:

$$\int{\left(x^{2} - 7 x\right)d x} = \frac{x^{2} \left(2 x - 21\right)}{6}+C$$

$$$\int \left(x^{2} - 7 x\right)\, dx = \frac{x^{2} \left(2 x - 21\right)}{6} + C$$$A