[其他] 交錯級數:1-1/2 +1/3 -1/4 +1/5 -1/6 +
交錯級數:
1-1/2 +1/3 -1/4 +1/5 -1/6 +..........
重新排列成:
(1-1/2)-1/4 +(1/3-1/6)-1/8+(1/5-1/10)-1/12 +......
= 1/2-1/4 +1/6-1/8+1/10-1/12 +.......
= 1/2 ( 1-1/2 +1/3 -1/4 +1/5 -1/6 +.........)
另外:1-1/2 +1/3 -1/4 +1/5 -1/6 +.........收斂值為 ln2=0.693
上面等式變成 ln2 = 1/2 (ln2) 這怪異結果,為何?
參考資料
https://www.ptt.cc/bbs/Gossiping/M.1484325449.A.857.html
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