导数和微分公式

导数和微分基本公式汇总

cot=1/tanx=cosx/sinx

sec=1/cosx，cscx=1/sinx

$tan^2$a+1=$sec^2$a，$cot^2$a+1=$csc^2$a
$tan^2$a=$sec^2$a - 1

sin2x=2sinxcosx

(dx)需要求导之后才能消失

$sin^2x = \frac{1-cos2x}{2}$

$cos^2x = \frac{1+cos2x}{2}$

​