$$$\sin{\left(x \right)} - \cos{\left(x \right)}$$$の導関数
関連する計算機: 対数微分計算機, 陰関数微分計算機(手順付き)
入力内容
$$$\frac{d}{dx} \left(\sin{\left(x \right)} - \cos{\left(x \right)}\right)$$$ を求めよ。
解答
和/差の導関数は、導関数の和/差である:
$${\color{red}\left(\frac{d}{dx} \left(\sin{\left(x \right)} - \cos{\left(x \right)}\right)\right)} = {\color{red}\left(\frac{d}{dx} \left(\sin{\left(x \right)}\right) - \frac{d}{dx} \left(\cos{\left(x \right)}\right)\right)}$$余弦関数の導関数は$$$\frac{d}{dx} \left(\cos{\left(x \right)}\right) = - \sin{\left(x \right)}$$$:
$$- {\color{red}\left(\frac{d}{dx} \left(\cos{\left(x \right)}\right)\right)} + \frac{d}{dx} \left(\sin{\left(x \right)}\right) = - {\color{red}\left(- \sin{\left(x \right)}\right)} + \frac{d}{dx} \left(\sin{\left(x \right)}\right)$$正弦関数の導関数は$$$\frac{d}{dx} \left(\sin{\left(x \right)}\right) = \cos{\left(x \right)}$$$:
$$\sin{\left(x \right)} + {\color{red}\left(\frac{d}{dx} \left(\sin{\left(x \right)}\right)\right)} = \sin{\left(x \right)} + {\color{red}\left(\cos{\left(x \right)}\right)}$$簡単化せよ:
$$\sin{\left(x \right)} + \cos{\left(x \right)} = \sqrt{2} \sin{\left(x + \frac{\pi}{4} \right)}$$したがって、$$$\frac{d}{dx} \left(\sin{\left(x \right)} - \cos{\left(x \right)}\right) = \sqrt{2} \sin{\left(x + \frac{\pi}{4} \right)}$$$。
解答
$$$\frac{d}{dx} \left(\sin{\left(x \right)} - \cos{\left(x \right)}\right) = \sqrt{2} \sin{\left(x + \frac{\pi}{4} \right)}$$$A