코시 응집 판정법
💡Theorem
\( \{ a_n \}_{n=1}^{\infty}\,\,\, satisfy: \)
1. \( a_n \geq 0 \)
2. \( a_{n+1} \leq a_n \)
Than
\( \displaystyle \sum_{n=1}^{\infty} a_n \,\, \) converge \( \,\, \displaystyle \Leftrightarrow \sum_{m=0}^{\infty} 2^m a_{2^m} \,\, \) converge
ㅤ
ㅤ
증명
처음으로 \( \displaystyle \sum_{m=0}^{\infty} 2^
