请各位学霸帮帮忙,把每一步计算都写出来,能作说明就说明,谢谢!
3个回答
展开全部
(1)
=根号(n-1)-根号n
(2)题
1/(1+√2)+1/(√2+√3)+1/(√3+√4)+.....+1/(√98+√99)+1/(√99+√100)
=(√2-1)/(√2+1)(√2-1)+(√3-√2)/(√3+√2)(√3-√2)+(√4-√3)/(√4+√3)(√4-√3)+.....+(√99-√98)/(√99+√98)(√99-√98)+(√100-√99)/(√100+√99)(√100-√99)
=√2-1+√3-√2+√4-√3+.....+√99-√98+√100-√99
=√100-1
=10-1
=9
=根号(n-1)-根号n
(2)题
1/(1+√2)+1/(√2+√3)+1/(√3+√4)+.....+1/(√98+√99)+1/(√99+√100)
=(√2-1)/(√2+1)(√2-1)+(√3-√2)/(√3+√2)(√3-√2)+(√4-√3)/(√4+√3)(√4-√3)+.....+(√99-√98)/(√99+√98)(√99-√98)+(√100-√99)/(√100+√99)(√100-√99)
=√2-1+√3-√2+√4-√3+.....+√99-√98+√100-√99
=√100-1
=10-1
=9
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询