1/(2*4)+1/(4*6)+1/(6*8)+········+1/(2006*2008)等于?

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1/(2*4)+1/(4*6)+1/(6*8)+········+1/(2006*2008)等于?
1/(2*4)+1/(4*6)+1/(6*8)+········+1/(2006*2008)等于?

1/(2*4)+1/(4*6)+1/(6*8)+········+1/(2006*2008)等于?
1/(2*4)+1/(4*6)+1/(6*8)+········+1/(2006*2008)
=1/2*(1/2-1/4)+1/2*(1/4-1/6)+……+1/2*(1/2006-1/2008)
=1/2*(1/2-1/4+1/4-1/6+……+1/2006-1/2008)
=1/2*(1/2-1/2008)
=1003/4016

1/(2*4) = 0.5 * (1/2-1/4)
后面每个都这么拆
最后变为 0.5 * (1/2-1/4 + 1/4-1/6 + ... + 1/2006-1/2008)
= 0.5 * (1/2- 1/2008) = 1003/4016