Question

已知x=7+4根号3,y=7-4根号3,求x/y+y/x的值

Answer 1

已知x=7+4根号3,y=7-4根号3,

x/y+y/x

=(x²+y²)/(xy)

=[(x+y)²-2xy]/(xy)

=[14²-2×(7+4√3)×(7-4√3)]/(7+4√3)(7-4√3)

=(196-2)/2

=97;