Integral of $$$- x^{4} + x^{2}$$$

Find $$$\int \left(- x^{4} + x^{2}\right)\, dx$$$.

Integrate term by term:

$${\color{red}{\int{\left(- x^{4} + x^{2}\right)d x}}} = {\color{red}{\left(\int{x^{2} d x} - \int{x^{4} d x}\right)}}$$

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

$$- \int{x^{4} d x} + {\color{red}{\int{x^{2} d x}}}=- \int{x^{4} d x} + {\color{red}{\frac{x^{1 + 2}}{1 + 2}}}=- \int{x^{4} d x} + {\color{red}{\left(\frac{x^{3}}{3}\right)}}$$

Apply the power rule $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$ with $$$n=4$$$:

$$\frac{x^{3}}{3} - {\color{red}{\int{x^{4} d x}}}=\frac{x^{3}}{3} - {\color{red}{\frac{x^{1 + 4}}{1 + 4}}}=\frac{x^{3}}{3} - {\color{red}{\left(\frac{x^{5}}{5}\right)}}$$

Therefore,

$$\int{\left(- x^{4} + x^{2}\right)d x} = - \frac{x^{5}}{5} + \frac{x^{3}}{3}$$

Add the constant of integration:

$$\int{\left(- x^{4} + x^{2}\right)d x} = - \frac{x^{5}}{5} + \frac{x^{3}}{3}+C$$

$$$\int \left(- x^{4} + x^{2}\right)\, dx = \left(- \frac{x^{5}}{5} + \frac{x^{3}}{3}\right) + C$$$A