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$$$108 \cos{\left(x^{2} \right)}$$$ 的积分
您的输入
求$$$\int 108 \cos{\left(x^{2} \right)}\, dx$$$。
解答
对 $$$c=108$$$ 和 $$$f{\left(x \right)} = \cos{\left(x^{2} \right)}$$$ 应用常数倍法则 $$$\int c f{\left(x \right)}\, dx = c \int f{\left(x \right)}\, dx$$$：
$${\color{red}{\int{108 \cos{\left(x^{2} \right)} d x}}} = {\color{red}{\left(108 \int{\cos{\left(x^{2} \right)} d x}\right)}}$$
该积分（菲涅耳余弦积分）没有闭式表达式：
$$108 {\color{red}{\int{\cos{\left(x^{2} \right)} d x}}} = 108 {\color{red}{\left(\frac{\sqrt{2} \sqrt{\pi} C\left(\frac{\sqrt{2} x}{\sqrt{\pi}}\right)}{2}\right)}}$$
因此，
$$\int{108 \cos{\left(x^{2} \right)} d x} = 54 \sqrt{2} \sqrt{\pi} C\left(\frac{\sqrt{2} x}{\sqrt{\pi}}\right)$$
加上积分常数：
$$\int{108 \cos{\left(x^{2} \right)} d x} = 54 \sqrt{2} \sqrt{\pi} C\left(\frac{\sqrt{2} x}{\sqrt{\pi}}\right)+C$$
答案
$$$\int 108 \cos{\left(x^{2} \right)}\, dx = 54 \sqrt{2} \sqrt{\pi} C\left(\frac{\sqrt{2} x}{\sqrt{\pi}}\right) + C$$$A