Question

超难的数学题、做出给分啊、限制今天

Answer 1

x+1/x=(1-a)/a

两边平方

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

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

x^2/(x^4+x^2+1)

上下除x^2

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

=1/[(1-2a-a^2)/a^2+1]

=a^2/(1-2a)