x=0显然不是根两边同时除以x^2,得：x^2+1/x^2+2(x+1/x)-6=0令t=x+1/x,则x^2+1/x^2=t^2-2代入上式得：t^2-2+2t-6=0得：t^2+2t-8=0(t+4)(t-2)=0得：t=-4,2t=-4时,x+1/x=-4,x^2+4x+1=0,得：x=-2+√3,-2-√3t=2时,x+1/x=...