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        1. 在△ABC中,,記,△ABC的面積為,且滿足.
          (1)求的取值范圍;
          (2)求函數(shù)的最大值和最小值.
          (1)(2)

          試題分析:(1)由,得。
          ,∴。
          的取值范圍為。              6分
          (2)注意到=
          =                  8分
          ,∴。
          故當(dāng),即時(shí),;            10分
          故當(dāng),即時(shí),。              12分
          點(diǎn)評(píng):本題主要涉及到向量的數(shù)量積三角形面積的計(jì)算及三角函數(shù)性質(zhì),求最值時(shí)要注意自變量角的取值范圍
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