$$$2 x^{2} - y^{2}$$$ 关于$$$x$$$的积分
您的输入
求$$$\int \left(2 x^{2} - y^{2}\right)\, dx$$$。
解答
逐项积分:
$${\color{red}{\int{\left(2 x^{2} - y^{2}\right)d x}}} = {\color{red}{\left(\int{2 x^{2} d x} - \int{y^{2} d x}\right)}}$$
应用常数法则 $$$\int c\, dx = c x$$$,使用 $$$c=y^{2}$$$:
$$\int{2 x^{2} d x} - {\color{red}{\int{y^{2} d x}}} = \int{2 x^{2} d x} - {\color{red}{x y^{2}}}$$
对 $$$c=2$$$ 和 $$$f{\left(x \right)} = x^{2}$$$ 应用常数倍法则 $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$:
$$- x y^{2} + {\color{red}{\int{2 x^{2} d x}}} = - x y^{2} + {\color{red}{\left(2 \int{x^{2} d x}\right)}}$$
应用幂法则 $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$,其中 $$$n=2$$$:
$$- x y^{2} + 2 {\color{red}{\int{x^{2} d x}}}=- x y^{2} + 2 {\color{red}{\frac{x^{1 + 2}}{1 + 2}}}=- x y^{2} + 2 {\color{red}{\left(\frac{x^{3}}{3}\right)}}$$
因此,
$$\int{\left(2 x^{2} - y^{2}\right)d x} = \frac{2 x^{3}}{3} - x y^{2}$$
化简:
$$\int{\left(2 x^{2} - y^{2}\right)d x} = x \left(\frac{2 x^{2}}{3} - y^{2}\right)$$
加上积分常数:
$$\int{\left(2 x^{2} - y^{2}\right)d x} = x \left(\frac{2 x^{2}}{3} - y^{2}\right)+C$$
答案
$$$\int \left(2 x^{2} - y^{2}\right)\, dx = x \left(\frac{2 x^{2}}{3} - y^{2}\right) + C$$$A