解:x+(1/x)=2[x+(1/x)]^2=2^2x^2+2+(1/x)^2=4x^2+(1/x)^2=2[x^2+(1/x)^2]^2=2^2x^4+2+(1/x)^4=4x^4+(1/x)^4=2即:x^2+(1/x)^2=2x^4+(1/x)^4=2
x+(1/x)=2所以 (3/2)x=2所以 X=3所以带入x^2+(1/x^2)得2^2+(1/2^2)=4.25x^4+(1/x^4)=2^4+(1/4^4)=6562/81