Question

已知x的平方减4x加1等于0,求x的4次方加x的2次方+1分之x²的值

Answer 1

已知x的平方减4x加1等于0,

x-4+1/x=0

x+1/x=4

x^2+2+1/x^2=16

x^2+1/x^2=14

x的4次方加x的2次方+1分之x²的值

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

=1/(14+1)

=1/15