已知a=5+2√6,b=5-2√6,求b/a+a/b+2的值

Question

已知a=5+2√6,b=5-2√6,求b/a+a/b+2的值

Answer 1

a=根号5+2,=5+4+4√5=9+4√5 b=根号5-2,=9-4√5 ab=5-4=1 √为根号哈b/a+a/b+2=（a?+b?）/ab +2=9+4√5+9-4√5+2=18+2=20