|
|
|
|
|
|
|
|
|
|
|
|
$$$x^{2} - \frac{1}{x^{22}}$$$ 的積分
您的輸入
求$$$\int \left(x^{2} - \frac{1}{x^{22}}\right)\, dx$$$。
解答
逐項積分：
$${\color{red}{\int{\left(x^{2} - \frac{1}{x^{22}}\right)d x}}} = {\color{red}{\left(- \int{\frac{1}{x^{22}} d x} + \int{x^{2} d x}\right)}}$$
套用冪次法則 $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$，以 $$$n=2$$$：
$$- \int{\frac{1}{x^{22}} d x} + {\color{red}{\int{x^{2} d x}}}=- \int{\frac{1}{x^{22}} d x} + {\color{red}{\frac{x^{1 + 2}}{1 + 2}}}=- \int{\frac{1}{x^{22}} d x} + {\color{red}{\left(\frac{x^{3}}{3}\right)}}$$
套用冪次法則 $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$，以 $$$n=-22$$$：
$$\frac{x^{3}}{3} - {\color{red}{\int{\frac{1}{x^{22}} d x}}}=\frac{x^{3}}{3} - {\color{red}{\int{x^{-22} d x}}}=\frac{x^{3}}{3} - {\color{red}{\frac{x^{-22 + 1}}{-22 + 1}}}=\frac{x^{3}}{3} - {\color{red}{\left(- \frac{x^{-21}}{21}\right)}}=\frac{x^{3}}{3} - {\color{red}{\left(- \frac{1}{21 x^{21}}\right)}}$$
因此，
$$\int{\left(x^{2} - \frac{1}{x^{22}}\right)d x} = \frac{x^{3}}{3} + \frac{1}{21 x^{21}}$$
化簡：
$$\int{\left(x^{2} - \frac{1}{x^{22}}\right)d x} = \frac{7 x^{24} + 1}{21 x^{21}}$$
加上積分常數：
$$\int{\left(x^{2} - \frac{1}{x^{22}}\right)d x} = \frac{7 x^{24} + 1}{21 x^{21}}+C$$
答案
$$$\int \left(x^{2} - \frac{1}{x^{22}}\right)\, dx = \frac{7 x^{24} + 1}{21 x^{21}} + C$$$A