，，且，則銳角為

A． B． C． D．

D

解析試題分析：根據(jù)題意，由于，，且，那么則有，由于角為銳角，那么可知銳角=，故選D.
考點：向量的共線
點評：主要是考查了向量的共線的概念的運用，屬于基礎(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

是兩個向量，，，且，則與的夾角為(     )

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，則向量的夾角為

A．45° B．60° C．120° D．135°

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，滿足||="2," | |=l，且（+）⊥（），則與的夾角為

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

平面向量與的夾角為，=（2,0），="1" 則=（   ）

A．B．C．4D．12

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，，，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，則向量在向量上的投影為（  ）

A． B．3 C．4 D．5

查看答案和解析>>

同步練習(xí)冊答案