已知a+b=2,ab=1,求b/a+a/b的值b/a a/b是a分之b+b分之a

Question

已知a+b=2,ab=1,求b/a+a/b的值
b/a a/b是a分之b+b分之a

Answer 1

b/a+a/b
=(b^2+a^2)/ab
=(b^2+a^2+2ab-2ab)/ab
=[(a+b)^2-2ab]/ab
=(2^2-2)/1
=2