问题
选择题
已知数列{an}为等差数列,{bn}为等比数列,且满足:a1000+a1012=π,b1b14=-2,则tan
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答案
∵数列为等差数列,a1000+a1012=π,
∴a1+a2011=π
∵{bn}为等比数列,b1b14=-2,
∴b7b8=-2,
∴tan
=tana1+a2011 1-b7b8
=π 3
,3
故选D.
已知数列{an}为等差数列,{bn}为等比数列,且满足:a1000+a1012=π,b1b14=-2,则tan
|
∵数列为等差数列,a1000+a1012=π,
∴a1+a2011=π
∵{bn}为等比数列,b1b14=-2,
∴b7b8=-2,
∴tan
=tana1+a2011 1-b7b8
=π 3
,3
故选D.