Question

已知a+b=6，ab=5，求根号b/a+根号a/b的值

Answer 1

b/a+a/b=（b²+a²)/ab=（(a+b)²-2ab）/ab=26/5
∴原式=根号26/5

Answer 2

√b/a+√a/b
=√ab/a+√ab/b
=√ab(1/a+1/b)
=√ab(a+b)/ab
=√5*6/5
=6√5/5