differentiable operator

例句：

1. 1. The function isdifferentiable everywhere.
   这个函数处处可微。
2. 2. The equation is differentiable forall real numbers.
   对于所有实数，这个方程可微。
3. 3. Differentiable functionsare used to solve differential equations.
   可微函数用于解决微分方程。