推 midarmyman:那我說說思路吧 140.117.198.78 05/20 21:12
→ midarmyman:先把分母的x拆成兩個對數相加 140.117.198.78 05/20 21:12
→ midarmyman:你會發覺跟上下限還有分子很對稱 140.117.198.78 05/20 21:13
→ midarmyman:於是就考慮下面兩位大大的方法 140.117.198.78 05/20 21:13
→ midarmyman:不過最好先證明他收斂 才能用相加法則 140.117.198.78 05/20 21:34
→ henry9621205:謝謝解答 114.41.57.147 05/23 00:22