Question

若1/x+x=3,则x的平方除以（X的四次方加X的平方加1等于多少

Answer 1

x+1/x=3

两边平方

x^2+2*x*1/x+1/x^2=9

x^2+2+1/x^2=9

x^2+1/x^2=7

x^2/(x^4+x^2+1)

上下同除以x^2

=1/(x^2+1+1/x^2)

=1/(7+1)

=1/8