已知x+y=5,xy=3,求根号下x/y+根号下y/x的值=5√3/3还是=25/3.

Question

已知x+y=5,xy=3,求根号下x/y+根号下y/x的值=5√3/3还是= 25/3.

Answer 1

√(x/y)+√(y/x)
=√(xy)/y+√(xy)/x
=√(xy)*(x+y)/(xy)
=√3*5/3
=5√3/3