在△ABC中，角A，B，C所对的边分别为a，b，c，已知a，b，c成等比数列，且 sinAsinC=34 ．（Ⅰ）求角B的大小；（Ⅱ）若b=3，求△ABC的面积最大值．_刷题宝

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在△ABC中，角A，B，C所对的边分别为a，b，c，已知a，b，c成等比数列，且 sinAsinC=

3

4

．

（Ⅰ）求角B的大小；

（Ⅱ）若b=3，求△ABC的面积最大值．

上一题下一题 0.0难度选择题更新时间:2019-12-02 07:01:46

答案(点此获取答案解析）

解：（Ⅰ）因为a、b、c成等比数列，则b²=ac．

由正弦定理得sin²B=sinAsinC．

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