1/√ 2+1+1/√ 3+√ 2+1/√ 4+√ 3+····+1/√ 2009+√ 2008的值

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1/√2+1+1/√3+√2+1/√4+√3+····+1/√2009+√2008的值1/√2+1+1/√3+√2+1/√4+√3+····+1/√2009+√2008的值1/√2+1+1/√3+√2

1/√ 2+1+1/√ 3+√ 2+1/√ 4+√ 3+····+1/√ 2009+√ 2008的值
1/√ 2+1+1/√ 3+√ 2+1/√ 4+√ 3+····+1/√ 2009+√ 2008的值

1/√ 2+1+1/√ 3+√ 2+1/√ 4+√ 3+····+1/√ 2009+√ 2008的值
分母有理化
1/(√2+1)=(√2-1)/(√2+1)(√2-1)=√2-1
同理
1/(√3+√2)=√3-√2
后面以此类推
原式=√2-1+√3-√2+√4-√3+……+√2009-√2008
=√2009-1
=7√41-1

1/(√2+1)=(√2-1)/(√2+1)(√2-1)=√2-1
1/(√3+√2)=√3-√2
原式=√2-1+√3-√2+√4-√3+……+√2009-√2008
=√2009-1
=7√41-1