优优班--学霸训练营 > 知识点挑题
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            • 1. \(.\) 不等式组\(\begin{cases} 2x-y+1\geqslant 0, \\ x-2y+2\leqslant 0, \\ x+y-4\leqslant 0 \end{cases}\)的解集记作\(D\),实数\(x\),\(y\)满足如下两个条件:

              \(①∀(x,y)∈D\),\(y\geqslant ax\);

              \(②∃(x,y)∈D\),\(x-y\leqslant a\).

              则实数\(a\)的取值范围为________.

            • 2. 已知\(x\),\(y\)满足\( \begin{cases} x+y-2\geqslant 0 \\ x-2y+4\geqslant 0 \\ 2x+y-4\leqslant 0\end{cases}\),若\(ax+y\)的最小值为\(- \dfrac {2}{3}\),则\(a=(\)  \()\)
              A.\(- \dfrac {1}{4}\)
              B.\(- \dfrac {1}{3}\)
              C.\(- \dfrac {1}{2}\)
              D.\(-1\)
            • 3. 若变量 \(x\)\(y\)满足约束条件\(z\)\(=2\) \(x\)\(+\) \(y\)的最大值为\((\)  \()\)
              A.\(1\)
              B.\(2\)
              C.\(3\)
              D.\(4\)
            • 4.

              双曲线\( \dfrac{x^{2}}{a^{2}}- \dfrac{y^{2}}{b^{2}}=1(a > 0,b > 0)\)的两条渐近线将平面划分为“上、下、左、右”四个区域\((\)不含边界\()\),若点\((2,1)\)在“右”区域内,则双曲线离心率\(e\)的取值范围是\((\)  \()\)

              A.\(\left( \left. 1, \dfrac{ \sqrt{5}}{2} \right. \right)\)
              B.\(\left( \left. \dfrac{ \sqrt{5}}{2},+∞ \right. \right)\)

              C.\(\left( \left. 1, \dfrac{5}{4} \right. \right)\)
              D.\(\left( \left. \dfrac{5}{4},+∞ \right. \right)\)
            • 5.

              设实数\(x\)\(y\)满足约束条件\(\begin{cases}3x-y-6\leqslant 0, \\ x-y+2\geqslant 0, \\ x\geqslant 0, \\ y\geqslant 0,\end{cases}\)若目标函数\(z\)\(=\)\(ax\)\(+\)\(by\)\((\)\(a\)\( > 0\),\(b\)\( > 0)\)的最大值为\(10\),则\(a\)\({\,\!}^{2}+\)\(b\)\({\,\!}^{2}\)的最小值为________.

            • 6. \(.\) 不等式组\(\begin{cases} 2x-y+1\geqslant 0, \\ x-2y+2\leqslant 0, \\ x+y-4\leqslant 0 \end{cases}\)的解集记作\(D\),实数\(x\),\(y\)满足如下两个条件:

              \(①∀(x,y)∈D\),\(y\geqslant ax\);

              \(②∃(x,y)∈D\),\(x-y\leqslant a\).

              则实数\(a\)的取值范围为________.

            • 7.

              设变量\(x\),\(y\)满足约束条件\(\begin{cases} & x+y\leqslant a \\ & x+y\geqslant 8 \\ & x\geqslant 6 \end{cases}\),且不等式\(x+2y\leqslant 16\)恒成立,则实数\(a\)的取值范围是

              A.\([8,+∞)\)
              B.\((-∞,11]\)
              C.\([8,11]\)
              D.\([6,11]\)
            • 8. 设不等式组\(\begin{cases} x > 0, \\ y > 0, \\ y\leqslant -nx+3n \end{cases}\)所表示的平面区域为\(D\)\({\,\!}_{n}\),记\(D\)\({\,\!}_{n}\)内的整点\((\)横坐标和纵坐标均为整数的点\()\)个数为\(a\)\({\,\!}_{n}\)\((n∈N\)\({\,\!}^{*}\)\()\),若\(m > \)\( \dfrac{1}{a_{1}a_{2}}\)\(+\)\( \dfrac{1}{a_{2}a_{3}}\)\(+…+\)\( \dfrac{1}{a_{n}a_{n+1}}\)对于任意的正整数恒成立,则实数\(m\)的取值范围是\((\)  \()\)
              A.\(\left[ \left. \dfrac{1}{9},+∞ \right. \right)\)
              B.\(\left( \left. \dfrac{1}{9},+∞ \right. \right)\)

              C.\(\left( \left. -∞, \dfrac{1}{9} \right. \right]\)
              D.\(\left( \left. -∞, \dfrac{1}{9} \right. \right)\)
            • 9.

              已知不等式组\(\begin{cases} & 0\leqslant x\leqslant \pi \\ & y\leqslant \sin x+a \\ & y\geqslant 0 \\ \end{cases}\)所对应的平面区域面积为\(2+2\pi \),则\(\sqrt{3}x+2y+1\)的最大值为\((\)   \()\)

              A.\(\dfrac{5\sqrt{3}\pi }{6}+6\)
              B.\(\sqrt{3}\pi +7\)
              C.\(6\)
              D.\(7\)
            • 10.

              设\(x\),\(y\)满足约束条件\( \begin{cases} 3x-y-6\leqslant 0 \\ x-y+2\geqslant 0 \\ x\geqslant 0,y\geqslant 0\end{cases}\),若目标函数\(z=ax+by(a > 0,b > 0)\)的最大值为\(12\),则\( \dfrac {2}{a}+ \dfrac {3}{b}\)的最小值为\((\)  \()\)

              A.\( \dfrac {25}{6}\)
              B.\( \dfrac {8}{3}\)
              C.\( \dfrac {11}{3}\)
              D.\(4\)
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