优优班--学霸训练营 > 知识点挑题
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            • 1.

              已知\(|a|=1\),\(|b|= \sqrt{2}\),且\(a⊥(a-b)\),则向量\(a\)与向量\(b\)的夹角是________.

            • 2. 在平面直角坐标系\(xOy\)中,四边形\(ABCD\)的边\(AB/\!/DC\),\(AD/\!/BC\),已知点\(A(-2,0)\),\(B(6,8)\),\(C(8,6)\),则\(D\)点的坐标为_________________________.
            • 3.

              已知向量\(a=(-1,2)\),\(b=(m,1)\),若向量\(a+ b\)与\(a\)垂直,则\(m=\)_________.

            • 4. 已知在平行四边形\(ABCD\)中,\(\overrightarrow{AB}=(1,3)\),\(\overrightarrow{AC}=(2,5)\),则\(\overrightarrow{AD}\)在\(\overrightarrow{AC}\)上的投影为
              A.\(\dfrac{12\sqrt{5}}{2}\)
              B.\(\dfrac{12\sqrt{29}}{29}\)
              C.\(12\)
              D.\(\dfrac{46\sqrt{29}}{29}\)
            • 5. \(a·b=a·c(a\neq 0)\),则\(b=c.\)(    )

              A.\(√\)  
              B.\(×\)
            • 6. 已知向量\( \overrightarrow{a}=(-1,2)\),\( \overrightarrow{b}=(2,-2)\),则\( \overrightarrow{a}⋅( \overrightarrow{a}+ \overrightarrow{b})=\) ______ .
            • 7.

              已知\(| \overset{→}{OA} |=1\),\(| \overset{→}{OB} |=m\),\(∠AOB= \dfrac{3}{4} π\),点\(C\)在\(∠AOB\)内且\( \overset{→}{OA}· \overset{→}{OC} =0\),若\( \overset{→}{OC}=2λ \overset{→}{OA}+λ \overset{→}{OB} (λ\neq 0)\),则\(m=\)(    )

              A.\( \dfrac{ \sqrt{2}}{2} \)
              B.\(2 \sqrt{2} \)
              C.\(2\)
              D.\(3\)
            • 8. 已知向量 \(a\)\(b\)满足\(|\) \(a\)\(|=1\),\(|\) \(b\)\(|=4\),且 \(a·b\)\(=2\),则 \(a\)\(b\)的夹角 \(θ\)为(    )
              A.\( \dfrac{π}{6}\)                                     
              B.\( \dfrac{π}{4}\)
              C.\( \dfrac{π}{3}\)                                     
              D.\( \dfrac{π}{2}\)
            • 9.

              平面向量\(a与b \)的夹角为\(60^{\circ},a=(2,0),|b|=1,则|a+2b| \)等于(    )

              A.\(2\sqrt{2}\)
              B.\(2\sqrt{3}\)
              C.\(12\)
              D.\(\sqrt{10}\) 
            • 10.

              已知向量\(a\),\(b\)的夹角为\(60^{\circ}\), \(|\)\(a\) \(|=\)\(2\), \(|\)\(b\) \(|=\)\(3\),则 \(|\)\(2a\) \(-\)\(b\) \(|=\)____________   

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