Question

设等差数列{an},{bn} 的前n项和Sn,Tn满足Sn/Tn=An+1/2n+7,且a3/(b4+b6)+a7/(b

Answer 1

(1)a3/(b4+b6) +a7/(b2+b8)=a3/(2*b5)+a7/(2*b5)=a5/b5=2/5a5/b5=S9/T9=(9A+1)/(2*9+7)=(9A+1)/25=2/5A=1(2)S2=k*2*(2A+1)=k*2*3=6k=1Sn=n(n+1)S(n-1)=n(n-1)an=2ny=g(x)=1/2(x-1)g(x)=(1/2)*(x-1)cn=1/2 *[c(n-1)-1...