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            • 1.

              已知\(a∈\left[ \dfrac{π}{2},π\right], \overrightarrow{a}=\left(2,-1\right), \overrightarrow{b}=\left(\cos a,\sin a\right), \)且\( \overrightarrow{a}/\!/ \overrightarrow{b} \).

              \((1)\)求\(\tan (\alpha +\dfrac{\pi }{4})\)的值;   

              \((2)\)求\(\cos (\dfrac{5\pi }{6}-2\alpha )\)的值.

            • 2.

              在\(\triangle ABC\)中,点\(D\)是边\(BC\)上任意一点,\(M\)是线段\(AD\)的中点,若存在实数\(λ\)和\(μ\),使得\(\overrightarrow{BM}=\lambda \overrightarrow{AB}+\mu \overrightarrow{AC}\),则\(\lambda +\mu =\)

              A.\(\dfrac{1}{2}\)
              B.\(-\dfrac{1}{2}\)
              C.\(2\)
              D.\(-2\)
            • 3.

              在\(\Delta ABC\)中,角\(A\),\(B\),\(C\)的对边分别是\(a\),\(b\),\(c\),且向量\(\overrightarrow{m}=(5a-4c,4b)\)与向量\(\overrightarrow{n}=(\cos C,\cos B)\)共线.

              \((1)\)求\(\cos B\);

              \((2)\)若\(b=\sqrt{10}\),\(c=5\),\(a < c\),且\(\overrightarrow{AD}=2\overrightarrow{DC}\),求\(BD\)的长度.

            • 4.

              \((1)\)设平面向量\(\overrightarrow{m}=(1,2)\),\(\overrightarrow{n}=(-2,x)\),若\(\overrightarrow{m}/\!/\overrightarrow{n}\),则\(|\overrightarrow{m}+2\overrightarrow{n}|= \)______

              \((2)\)在\(\triangle ABC\)中,\(a=3\),\(c=5\),\(B={{120}^{\circ }}\),则\(\dfrac{\sin B}{\sin C}=\)______

              \((3)\)等差数列\(\{{{a}_{n}}\}\)中,\({{a}_{1}}\),\({{a}_{3}}\),\({{a}_{4}}\)成等比数列,则公比为________

              \((4)\)已知数列\(\{{{a}_{n}}\}\)的前\(n\)项和\({{S}_{n}}=\dfrac{n+1}{n}\),则\(\{{{a}_{n}}\}\)的通项公式为__________

              \((5)\)在\(\Delta ABC\)中,\(D\)是\(BC\)的中点,已知\(∠BAD+∠C=90^{\circ}\),则\(\Delta ABC\)的形状为_____________

            • 5.

              已知\(\overrightarrow{a} \),\(\overrightarrow{b} \)是同一平面内的两个向量,其中\(\overrightarrow{a} =(1,-2)\),\(|\overrightarrow{b} |=2\sqrt{{5}} \).

              \((\)Ⅰ\()\)若\(\overrightarrow{a} /\!/\overrightarrow{b} \),求向量\(\overrightarrow{b} \)的坐标;

              \((\)Ⅱ\()\)若\((2\overrightarrow{a} -3\overrightarrow{b} )⋅(2\overrightarrow{a} +\overrightarrow{b} )=-20\),求\(\overrightarrow{a} \)与\(\overrightarrow{b} \)的夹角\(θ\)的值.

            • 6. 设两个向量\(a=(λ+2,λ^{2}-\cos ^{2}α)\)和\(b=(m,\dfrac{m}{2}+\sin \alpha )\),其中\(λ\)、\(m\)、\(α\)为实数\(.\)若\(a=2b\),则\(\dfrac{\lambda }{m}\)的取值范围是\((\)   \()\)
              A.\([-6,1]\)
              B.\([4,8]\)
              C.\((-∞,1]\)
              D.\([-1,6]\)
            • 7.

              已知向量\(\vec{a}=(m,1)\),\(\vec{b}=(1-n,2)\),\(\left( m > 0,n > 0 \right)\)若\(\overrightarrow{a}{/\!/}\overrightarrow{b}\),则\(\dfrac{1}{m}{+}\dfrac{8}{n}\)的最小值______ .

            • 8.

              \((1)\)已知变量\(x,y\)满足\(\begin{cases}x-4y+3⩽0 \\ \begin{matrix}x+y-4\leqslant 0 \\ x\geqslant 1\end{matrix}\end{cases} \),\( \dfrac{{x}^{2}+{y}^{2}}{xy} \)的取值范围为    

              \((2)\)若向量\(\mathbf{a}=\left( \cos \theta ,\cos \left( \theta +\dfrac{3\pi }{2} \right) \right),\mathbf{b}=\left( -1,2 \right)\)共线,则\({{\sin }^{4}}\theta +{{\cos }^{4}}\theta \)的值为   

              \((3)\)已知\(p:\exists {{x}_{0}}\in \mathbf{R},a\sin {{x}_{0}}+\cos {{x}_{0}}=-2\),\(q:f(x)=x-\dfrac{3}{4}a\ln x+\dfrac{3-a}{x}\)在\(\left[ 1,2 \right]\)上为减函数,则\(p\)是\(q\)的        条件.

              \((4)\)观察下列等式:\(\dfrac{3}{1\times 2}\times \dfrac{1}{2}=1-\dfrac{1}{{{2}^{2}}},\begin{matrix} {} & {} \\ \end{matrix}\dfrac{3}{1\times 2}\times \dfrac{1}{2}+\dfrac{4}{2\times 3}\times \dfrac{1}{{{2}^{2}}}=1-\dfrac{1}{3\times {{2}^{2}}},\dfrac{3}{1\times 2}\times \dfrac{1}{2}+\dfrac{4}{2\times 3}\times \dfrac{1}{{{2}^{2}}}+\dfrac{5}{3\times 4}\times \dfrac{1}{{{2}^{3}}}=1-\dfrac{1}{4\times {{2}^{3}}},\cdot \cdot \cdot \cdot \cdot \cdot \)

              由此推出则第\(n\)个等式为                 

              \((5)\)已知函数\(f(x)=\begin{cases} & \left| {{\log }_{2}}(x+2) \right|-m,x\in \left( -2,0 \right) \\ & \cos \left( \dfrac{\pi }{4}x \right)-m,x\in \left[ 0,8 \right] \\ \end{cases}\)有且仅有\(4\)个零点\({{x}_{1}},{{x}_{2}},{{x}_{3}},{{x}_{4}}\),且\({{x}_{1}} < {{x}_{2}} < {{x}_{3}} < {{x}_{4}}\),则\(\dfrac{({{x}_{3}}-2)({{x}_{4}}-2)}{{{x}_{1}}{{x}_{2}}+2({{x}_{1}}+{{x}_{2}})+5}\)的取值范围是        

            • 9.

              已知向量\( \overset{→}{m}=(a,b-6) \),\( \overset{→}{n}=(b+2,1) \).

              \((1)\)若\( \overset{→}{m} /\!/ \overset{→}{n} \),求的最小值;

              \((2)\)若\(a > 0,b > 0\)且\( \overset{→}{m}⊥ \overset{→}{n} \),求\(ab\)的最大值.

            • 10.

              向量\( \overset{→}{OA} =(\)\(k\),\(12)\),\( \overset{→}{OB} =(4,5)\),\( \overset{→}{OC} =(10,8)\),若\(A\)、\(B\)、\(C\)三点共线,则\(k\)\(= \)______.

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