Question

如果x+

1

x

=2，则

x2

x4+x2+1

=______．

Answer 1

∵（x+

1

x

）²=x²+2+

1

x2

=4，
∴x²+

1

x2

=2，
∴

x2

x4+x2+1

=

1

x2+1+ 1 x2

=

1

3

．
故本题答案为：

1

3

．