삼각 치환, trigonometric substitution
적분의 테크닉으로 쓰임. (삼각치환적분, integration by trigonometric substitution, ITS)
적분의 테크닉으로 쓰임. (삼각치환적분, integration by trigonometric substitution, ITS)
$\displaystyle \sqrt{a^2-x^2}$
$\displaystyle x=a\sin\theta$
$\displaystyle x=a\sin\theta$
$\displaystyle \sqrt{a^2+x^2}$
$\displaystyle x=a\tan\theta$
$\displaystyle x=a\tan\theta$
$\displaystyle \sqrt{x^2-a^2}$
$\displaystyle x=a\sec\theta$
$\displaystyle x=a\sec\theta$