已知 x+1/X=√8 ,求X-1/x的值? 初三数学!

2025-05-16 01:13:36
推荐回答(2个)
回答1:

x^2+1/x^2+2=8
x^2+1/x^2-2=4
x-1/x=2或-2

回答2:

x+1/x=√8
x>0
(x+1/x)²=8
x²+1/x²=6
(x-1/x)²=x²+1/x²-2=4
x-1/x=2