Question

高二等比数列已知a1与an+1与an关系式，求an通项，解题方法。高分急求 = =

若数列{an}满足a1=1/2，an+1=（（n+1）/n)an，则an=

Answer 1

a1=1/2
a2=2*a1
a3=3/2*a2
a4=4/3*a3
.
.
.
an=n/(n-1)*a(n-1)
相乘，得
a1*a2*a3...*an=1/2*2*3/2*4/3*...*n/(n-1)*a1*a2*...*a(n-1)
an=n/2