Bn分别是等差数列[an][bn]的前几项和,且An/Bn=(7n+45)/(n+3),求an/bn【详细过程,
问题描述:
Bn分别是等差数列[an][bn]的前几项和,且An/Bn=(7n+45)/(n+3),求an/bn【详细过程,
答
An,Bn分别是等差数列[an][bn]的前几项和,且An/Bn=(7n+45)/(n+3),求an/bn由于是等差数列:a1+a(2n-1) =2*a2 ;b1+b(2n-1) =2*b2 所以A(2n-1) =(2n-1)*(a1+a(2n-1))/2 =(2n-1)*anB(2n-1) =(2n-1)*(...