$$$a - t$$$ 對 $$$t$$$ 的導數
您的輸入
求$$$\frac{d}{dt} \left(a - t\right)$$$。
解答
和/差的導數等於導數的和/差:
$${\color{red}\left(\frac{d}{dt} \left(a - t\right)\right)} = {\color{red}\left(\frac{da}{dt} - \frac{d}{dt} \left(t\right)\right)}$$常數的導數為$$$0$$$:
$${\color{red}\left(\frac{da}{dt}\right)} - \frac{d}{dt} \left(t\right) = {\color{red}\left(0\right)} - \frac{d}{dt} \left(t\right)$$套用冪次法則 $$$\frac{d}{dt} \left(t^{n}\right) = n t^{n - 1}$$$,取 $$$n = 1$$$,也就是 $$$\frac{d}{dt} \left(t\right) = 1$$$:
$$- {\color{red}\left(\frac{d}{dt} \left(t\right)\right)} = - {\color{red}\left(1\right)}$$因此,$$$\frac{d}{dt} \left(a - t\right) = -1$$$。
答案
$$$\frac{d}{dt} \left(a - t\right) = -1$$$A