(1)x^3-2x+1=0
问题描述：
(1)x^3-2x+1=0
(2)2(x^2+1/x^2)-3(x+1/x)-1=0
答
(1)x^3-2x+1=0(x^3-x)-x+1=0x(x+1)(x-1)-(x-1)=0(x-1)(x^2+x-1)=0x-1=0,x^2+x-1=0x=1,x=(-1+√5)/2,x=(-1-√5)/2(2)2(x^2+1/x^2)-3(x+1/x)-1=0令a=x+1/xa^2=x^2+2+1/x^2x^2+1/x^2=a^2-22(a^2-2)-3a-1=02a^2-3a-5=0(a...