日韩亚洲一区中文字幕,日韩欧美三级中文字幕在线,国产伦精品一区二区三区,免费在线欧美性爱链接

      1. <sub id="o5kww"></sub>
        <legend id="o5kww"></legend>
        <style id="o5kww"><abbr id="o5kww"></abbr></style>

        <strong id="o5kww"><u id="o5kww"></u></strong>
        1. 在邊長為的正三角形ABC中,設(shè),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(shù)量積的運用
          點評:熟練掌握向量的夾角及數(shù)量積的定義是解決此類問題的關(guān)鍵,屬基礎(chǔ)題

          練習(xí)冊系列答案
          相關(guān)習(xí)題

          科目:高中數(shù)學(xué) 來源: 題型:單選題

          在ΔABC中,已知D是AB邊上一點,,則實數(shù)λ=

          A.- B.- C. D.

          查看答案和解析>>

          科目:高中數(shù)學(xué) 來源: 題型:單選題

          已知,則

          A.B.C.D.

          查看答案和解析>>

          科目:高中數(shù)學(xué) 來源: 題型:單選題

          若向量滿足,且,則向量的夾角為

          A.30°B.45°C.60°D.120°

          查看答案和解析>>

          科目:高中數(shù)學(xué) 來源: 題型:單選題

          已知向量,,若共線,則 (    )

          A. B. C. D.

          查看答案和解析>>

          科目:高中數(shù)學(xué) 來源: 題型:單選題

          已知,,,點C在內(nèi), ,若=2m+m),則=(    )                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         

          A.1B.2C.D.4

          查看答案和解析>>

          科目:高中數(shù)學(xué) 來源: 題型:單選題

          已知向量,若,則實數(shù)的取值范圍是(     )

          A. B.
          C. D.

          查看答案和解析>>

          科目:高中數(shù)學(xué) 來源: 題型:單選題

          在平行四邊形ABCD中,等于(  )

          A. B. C. D.

          查看答案和解析>>

          科目:高中數(shù)學(xué) 來源: 題型:單選題

          如圖,已知圓,四邊形為圓的內(nèi)接正方形,分別為邊、的中點,當(dāng)正方形繞圓心轉(zhuǎn)動時,的取值范圍是(    )

          A. B.
          C. D.

          查看答案和解析>>

          同步練習(xí)冊答案