Question

比较X^6+1和X^4+X^2的大小,X属于R.

Answer 1

x^6+1-(x^4+x^2)

=x^6-x^4-(x^2-1)

=x^2(x^2-1)-(x^2-1)

=(x^2-1)^2大于等于0

因此x^6+1≥x^4+x^2