若1,a1,a2,4成等差数列:1,b1,b2,b3,4成等比数列,则
的值等于___ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/116c015cf1468082b8184350e30d41a0.png)
20-21高二·全国·课后作业 查看更多[2]
更新时间:2020-09-18 13:58:00
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