高一数学数列通项的求法a1=1 an前n项和Sn=n^2*an求an=_数学解答

高一数学数列通项的求法
a1=1 an前n项和Sn=n^2*an求an=

人气：357 ℃　时间：2020-04-29 13:05:30

解答

(n+1)^2*a(n+1) = S(n+1) = S(n) + a(n+1) = n^2*a(n) + a(n+1),n(n+2)a(n+1) = n^2a(n),(n+2)a(n+1) = na(n),a(n+1)/a(n) = n/(n+2)a(n)/a(n-1) = (n-1)/(n+1)...a(2)/a(1) = 1/3a(n+1)/a(1) = [n*(n-1)*...*2*1]/[...