導數: 微積分裡向交關重要亇基礎概念

佢亇定義是：

${\displaystyle f'(x)=\lim _{h\to 0}{f(x+h)-f(x) \over h}}$

${\displaystyle f'(c)=0}$ 
${\displaystyle f'(ax)=a}$ 
${\displaystyle f'(\sin x)=\cos x}$ 
${\displaystyle f'(e^{x})=e^{x}}$ 
${\displaystyle f'(a^{x})=a^{x}\ln a}$ 
${\displaystyle f'(\log _{a}x)={1 \over (x\ln a)}}$