3ea9c223e4df07a86ba887f84481766e43822abc701846ec82b1bbe311bc6385c7fb4b4486de1db66f675a77fa4dd2

1ebec223e0dc2bae61abe9e74683706cbe0acabc2181f97f61ab04a1f9ab8d31889b2174b19688c8b1c8

n승일 때 ln씌우는 기법(교과서예제)