已知数列{an}:a1=1,当n大于等于2时,a1*a2*a3*…*an=n^2,求a3+a5的值
问题描述:
已知数列{an}:a1=1,当n大于等于2时,a1*a2*a3*…*an=n^2,求a3+a5的值
答
a1*a2*a3*…*a5=5^2=25,
a1*a2*a3*…*a4=4^2=16,
a5=25/16,
a1*a2*a3=3^2=9,
a1*a2=2^2=4,
a3=9/4,
a3+a5=61/16.