13/01/13 23:08:03.62
>>305
1/n - 1/(n+1) = 1/n(n+1) だから1/n = 1/(n+1) + 1/n(n+1)
1/2 = 1/3 + 1/6
1/3 = 1/4 + 1/12
1/4 = 1/5 + 1/20
……
13/01/13 23:08:03.62
>>305
1/n - 1/(n+1) = 1/n(n+1) だから1/n = 1/(n+1) + 1/n(n+1)
1/2 = 1/3 + 1/6
1/3 = 1/4 + 1/12
1/4 = 1/5 + 1/20
……