$$$12 x^{2} - 435 x$$$ 的積分
您的輸入
求$$$\int \left(12 x^{2} - 435 x\right)\, dx$$$。
解答
逐項積分:
$${\color{red}{\int{\left(12 x^{2} - 435 x\right)d x}}} = {\color{red}{\left(- \int{435 x d x} + \int{12 x^{2} d x}\right)}}$$
套用常數倍法則 $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$,使用 $$$c=435$$$ 與 $$$f{\left(x \right)} = x$$$:
$$\int{12 x^{2} d x} - {\color{red}{\int{435 x d x}}} = \int{12 x^{2} d x} - {\color{red}{\left(435 \int{x d x}\right)}}$$
套用冪次法則 $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$,以 $$$n=1$$$:
$$\int{12 x^{2} d x} - 435 {\color{red}{\int{x d x}}}=\int{12 x^{2} d x} - 435 {\color{red}{\frac{x^{1 + 1}}{1 + 1}}}=\int{12 x^{2} d x} - 435 {\color{red}{\left(\frac{x^{2}}{2}\right)}}$$
套用常數倍法則 $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$,使用 $$$c=12$$$ 與 $$$f{\left(x \right)} = x^{2}$$$:
$$- \frac{435 x^{2}}{2} + {\color{red}{\int{12 x^{2} d x}}} = - \frac{435 x^{2}}{2} + {\color{red}{\left(12 \int{x^{2} d x}\right)}}$$
套用冪次法則 $$$\int x^{n}\, dx = \frac{x^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$,以 $$$n=2$$$:
$$- \frac{435 x^{2}}{2} + 12 {\color{red}{\int{x^{2} d x}}}=- \frac{435 x^{2}}{2} + 12 {\color{red}{\frac{x^{1 + 2}}{1 + 2}}}=- \frac{435 x^{2}}{2} + 12 {\color{red}{\left(\frac{x^{3}}{3}\right)}}$$
因此,
$$\int{\left(12 x^{2} - 435 x\right)d x} = 4 x^{3} - \frac{435 x^{2}}{2}$$
化簡:
$$\int{\left(12 x^{2} - 435 x\right)d x} = \frac{x^{2} \left(8 x - 435\right)}{2}$$
加上積分常數:
$$\int{\left(12 x^{2} - 435 x\right)d x} = \frac{x^{2} \left(8 x - 435\right)}{2}+C$$
答案
$$$\int \left(12 x^{2} - 435 x\right)\, dx = \frac{x^{2} \left(8 x - 435\right)}{2} + C$$$A