若x^2-5x-1=0,则x^2−1/x^2=________.
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/14 12:58:18
![若x^2-5x-1=0,则x^2−1/x^2=________.](/uploads/image/z/2001845-29-5.jpg?t=%E8%8B%A5x%5E2-5x-1%3D0%2C%E5%88%99x%5E2%26%238722%3B1%2Fx%5E2%3D________%EF%BC%8E)
x){ѽ"H״B@iL OMPȶ{lIӠ_`gCOg/xcBXYgÓK|
[SP6 #sF m]bgv>ndlP`5:L6BuY$ف| 4v)
若x^2-5x-1=0,则x^2−1/x^2=________.
若x^2-5x-1=0,则x^2−1/x^2=________.
若x^2-5x-1=0,则x^2−1/x^2=________.
因为x^2-5x-1=0
所以x-1/x=5
x^2+1/x^2=27
(x+1/x)^2=29
x+1/x=正负根号28
所以x^2-1/x^2=(x+1/x)(x-1/x)=正负5倍根号29