28b9d932da836ef438ee80e64f837c6f407c74aff53b3ee0abb084b86913f777da2d

int. f(g(x))g'(x)dx=int. f(t)dt << 씹게이
int. f(g(x))g'(x)dx=int. f(g(x))dg(x) << 상남자