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在邊長為的正三角形ABC中,設,則等于( )

A.0 B.1 C.3 D.-3

D

解析試題分析:∵三角形ABC為邊長為的正三角形,∴,故選D
考點:本題考查了數量積的運用
點評:熟練掌握向量的夾角及數量積的定義是解決此類問題的關鍵,屬基礎題

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