共50条信息
已知\(\triangle ABC\)的外接圆的圆心为\(O\),半径为\(1\),若\(2\overrightarrow{AO}=\overrightarrow{AB}+\overrightarrow{AC}\),且\(| \overrightarrow{AO}|=| \overrightarrow{AB}|\),则向量\(\overrightarrow{CA}\)在向量\(\overrightarrow{BC}\)方向上的投影为
设\({{e}_{1}}\),\({{e}_{2}}\)为单位向量,其中向量\(a=2{{e}_{1}}+{{e}_{2}}\),向量\(b={{e}_{2}}\),且向量\(a\)在\(b\)上的投影为\(2\),则\({{e}_{1}}\)与\({{e}_{2}}\)的夹角为
\(∆ABC \)外接圆圆心为\(O\),半径为\(1\),\(2 \overrightarrow{AO}= \overrightarrow{AB}+ \overrightarrow{AC} \)且\(\left| \overrightarrow{OA}\right|=\left| \overrightarrow{AB}\right| \),则向量\(\overrightarrow{BA} \)在\(\overrightarrow{BC} \)方向上的投影为_______.
已知\(|a|=1\),\(|b|=2\),\(a\)与\(b\)的夹角为\(60^{\circ}\),则\(a+b\)在\(a\)上的投影为________.
已知\(\overrightarrow{a}\cdot \overrightarrow{b}=12\),\(\left| \overrightarrow{a} \right|{=3,}\left| \overrightarrow{b} \right|{=5}\) ,则\(\overrightarrow{b}\)在\(\overrightarrow{a}\)方向上的投影为 .
已知向量\(\overrightarrow{a}=(1,\sqrt{3})\),\(\overrightarrow{b}=(3,m)\),且\(\overrightarrow{b}\)在\(\overrightarrow{a}\)上的投影为\(-3\),则向量\(\overrightarrow{a}\)与\(\overrightarrow{b}\)夹角为____________.
向量\( \overset{⇀}{a}=(-1,3) \),\( \overset{⇀}{b}=(3,-4) \),则向量\( \overset{⇀}{a} \)在向量\( \overset{⇀}{b} \)方向上的投影为__________.
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