$x_1<x_2\text{,}f\left(x_1\right)<f\left(x_2\right)ㄹㄹㄹ$ㅁㄴㅇㄹㅇㄴㅁㄹㅇㅁㄴㄹㅁㄴㄹㅇㅁㅇㄴㄹ

$666_{89\times9\degree\int_0^{\infty}\!88\,dx}$ㅁㄴㄴㅁㅁㄴ

\left(\frac{x^{2}+2x+1}{\sqrt{x+1}}\right)\times\t

\left(\frac{x^{2}+2x+1}{\sqrt{x+1}}\right)\times\t