已知X²-3X+1=0 求下列各式的值 (1)x² +x²分之1 (2)x³+x...
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发布时间：2024-10-01 21:25
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热心网友
时间：2024-10-09 04:31
xx-3x+1=0
=>
x+1/x = 3
=>
xx + 1/xx = (x+1/x)^2 - 2 = 7
(2)
xxx+1/xxx = (1/x + x )(xx+1/xx) - (1/x + x) = 7*3-3=18
(3)
xxxxx+1/xxxxx = (1/xx+xx)(xxx+1/xxx) - (1/x+x) = 18*7-3=123
