问题
填空题
等比数列{an}中,若 a1a2a3=1,a2a3a4=8,则公比q=______.
答案
∵a1a2a3=(a1a3)a2=a23=1,a2a3a4=(a2a4)a3=a33=8,
∴a2=1,a3=2,
则公比q=
=2.a3 a2
故答案为:2
等比数列{an}中,若 a1a2a3=1,a2a3a4=8,则公比q=______.
∵a1a2a3=(a1a3)a2=a23=1,a2a3a4=(a2a4)a3=a33=8,
∴a2=1,a3=2,
则公比q=
=2.a3 a2
故答案为:2