1)由X^2-3X+1=0可知x不等于0两边除以x得X+1/X=3X^2/(X^4+x^2+1)=1/(x^2+1+1/X^2)=1/[(X+1/X)^2-2+1]=1/(9-1)=1/82)由X^2-3X+1=0可知x不等于0两边除以x得X+1/X=3X^2/X^4+x^2+1=1/x^2+x^2+1=(1/x+x)^2-2+1=9-1=8
