化简:1/(4+√(59+30√2))+1/(3-√(66-40√2))结果是

来源:百度知道 编辑:UC知道 时间:2024/05/05 08:55:00
化简:1/(4+√(59+30√2))+1/(3-√(66-40√2))结果是

59+30根号2=9+50+2*3*5根号2=(3+5根号2)方
根号(59+30根号2)=3+5根号2
1/(4+3+5根号2)=(7-5根号2)/(49-50)=5根号2-7

66-40根号2=16+50-2*4*5根号2=(4-5根号2)方
根号(66-40根号2)=5根号2-4
1/(3-5根号2+4)=(7+5根号2)/(49-50)=-7-5根号2

原式=5根号2-7-7-5根号2=-14

1/(4+√(59+30√2))+1/(3-√(66-40√2))
=1/(4+√(9+2*3*5√2+50))+1/(3-√(16-2*4*5√2+50))
=1/(4+√(3+5√2)^2)+1/(3-√(4-5√2)^2)
=1/(4+3+5√2)+1/(3-5√2+4)
=1/(7+5√2)+1/(7-5√2)
=-14