等比数列{an}满足:a2+a6=34π/3,a2·a6=64π/9,则sin(a4)=

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等比数列{an}满足:a2+a6=34π/3,a2·a6=64π/9,则sin(a4)=

数列{an}是等比数列,则:
a2×a6=(a4)²
则:
(a4)²=64π/9
a4=±8π/3
则:
sin(a4)=sin(±8π/3)=±√3/2