Difference between r1.2 and the current

@@ -1,7 +1,5 @@

= Theorem =

$\int\tan x dx$

$=-\ln|\cos x|+C$

$=\ln|\sec x|+C$

> $\int\tan x dx=-\ln|\cos x|+C=\ln|\sec x|+C$

= Proof =
$\int\tan x dx$

Theorem ¶

$\displaystyle \int\tan x dx=-\ln|\cos x|+C=\ln|\sec x|+C$

$\displaystyle \int\tan x dx$
$\displaystyle =\int\frac{\sin x}{\cos x}dx$

치환:
$\displaystyle u=\cos x$
$\displaystyle du=-\sin x dx$
$\displaystyle \sin x dx=-du$