∵1/1*3=1/2*(1/1-1/3)
1/3*5=1/2*(1/3-1/5)
1/5*7=1/2*(1/5-1/7)
……
1/95*97=1/2*(1/95-1/97)
1/97*99=1/2*(1/97-1/99)
∴原式就=1/2*(1/1-1/3)+1/2*(1/3-1/5)+1/2*(1/5-1/7)+……+1/2*(1/95-1/97)+1/2*(1/97-1/99)
=1/2*(1/1-1/3+1/3-1/5+1/5-1/7+……+1/95-1/97+1/97-1/99)
=1/2*(1-1/99)
=1/2*(98/99)
=49/99
1/1*3+1/3*5+1/5*7+...+1/95*97+1/97*99
1/1*3+1/3*5+1/5*7+...+1/95*97+1/97*99
数学人气:494 ℃时间:2020-01-30 07:40:28
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