$$$- \epsilon_{k} + z$$$ 关于 $$$\epsilon_{k}$$$ 的导数
您的输入
求$$$\frac{d}{d\epsilon_{k}} \left(- \epsilon_{k} + z\right)$$$。
解答
和/差的导数等于导数的和/差:
$${\color{red}\left(\frac{d}{d\epsilon_{k}} \left(- \epsilon_{k} + z\right)\right)} = {\color{red}\left(- \frac{d}{d\epsilon_{k}} \left(\epsilon_{k}\right) + \frac{dz}{d\epsilon_{k}}\right)}$$应用幂法则 $$$\frac{d}{d\epsilon_{k}} \left(\epsilon_{k}^{n}\right) = n \epsilon_{k}^{n - 1}$$$,取 $$$n = 1$$$,也就是说,$$$\frac{d}{d\epsilon_{k}} \left(\epsilon_{k}\right) = 1$$$:
$$- {\color{red}\left(\frac{d}{d\epsilon_{k}} \left(\epsilon_{k}\right)\right)} + \frac{dz}{d\epsilon_{k}} = - {\color{red}\left(1\right)} + \frac{dz}{d\epsilon_{k}}$$常数的导数是$$$0$$$:
$${\color{red}\left(\frac{dz}{d\epsilon_{k}}\right)} - 1 = {\color{red}\left(0\right)} - 1$$因此,$$$\frac{d}{d\epsilon_{k}} \left(- \epsilon_{k} + z\right) = -1$$$。
答案
$$$\frac{d}{d\epsilon_{k}} \left(- \epsilon_{k} + z\right) = -1$$$A