在等比数列{an}中,a1=1,a10=3,则a2a3a4a5a6a7a8a9=_.
问题描述:
在等比数列{an}中,a1=1,a10=3,则a2a3a4a5a6a7a8a9=______.
答
因为a1•a10=1×3=3,所以a2a3a4a5a6a7a8a9=(a2a9)(a3a8)(a4a7)(a5a6)=34=81
在等比数列{an}中,a1=1,a10=3,则a2a3a4a5a6a7a8a9=______.
因为a1•a10=1×3=3,所以a2a3a4a5a6a7a8a9=(a2a9)(a3a8)(a4a7)(a5a6)=34=81