$$$x^{2} - 2 y$$$ 對 $$$x$$$ 的積分
您的輸入
求$$$\int \left(x^{2} - 2 y\right)\, dx$$$。
解答
逐項積分:
$${\color{red}{\int{\left(x^{2} - 2 y\right)d x}}} = {\color{red}{\left(\int{x^{2} d x} - \int{2 y d x}\right)}}$$
套用冪次法則 $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$,以 $$$n=2$$$:
$$- \int{2 y d x} + {\color{red}{\int{x^{2} d x}}}=- \int{2 y d x} + {\color{red}{\frac{x^{1 + 2}}{1 + 2}}}=- \int{2 y d x} + {\color{red}{\left(\frac{x^{3}}{3}\right)}}$$
配合 $$$c=2 y$$$,應用常數法則 $$$\int c\, dx = c x$$$:
$$\frac{x^{3}}{3} - {\color{red}{\int{2 y d x}}} = \frac{x^{3}}{3} - {\color{red}{\left(2 x y\right)}}$$
因此,
$$\int{\left(x^{2} - 2 y\right)d x} = \frac{x^{3}}{3} - 2 x y$$
化簡:
$$\int{\left(x^{2} - 2 y\right)d x} = \frac{x \left(x^{2} - 6 y\right)}{3}$$
加上積分常數:
$$\int{\left(x^{2} - 2 y\right)d x} = \frac{x \left(x^{2} - 6 y\right)}{3}+C$$
答案
$$$\int \left(x^{2} - 2 y\right)\, dx = \frac{x \left(x^{2} - 6 y\right)}{3} + C$$$A