Question

初二数学的一道题求详细过程. 已知：x^2-3x+1=0,求根号下（x^2+1/x^2-2)的值.括号内的数全部都在根号

Answer 1

x^2－3x+1=0

x不等于0

两边除以x,得到

x-3+1/x=0

x+1/x=3

x^2+1/x^2

=(x+1/x)^2-2

=3^2-2

=7

根号(x^2+1/x^2-2)

=根号(7-2)

=根号5