优优班--学霸训练营 > 知识点挑题
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            • 1.

              函数\(f(x){=}\dfrac{1}{\sqrt{ax^{2}{+}3ax{+}1}}\)的定义域为\(R\),则实数\(a\)的取值范围是\(({  })\)


              A.\((0{,}\dfrac{4}{9})\)
              B.\({[}0{,}\dfrac{4}{9}{{]}}\)
              C.\({[}0{,}\dfrac{4}{9})\)
              D.\((0{,}\dfrac{4}{9}{{]}}\)
            • 2.

              函数\(y=\sqrt{\tan x\mathrm{{-}}1}\)的定义域是____\(.\) 

            • 3.

              已知函数\(f(x)=\begin{cases} 2(1-x),0\leqslant x\leqslant 1, \\ x-1,1 < x\leqslant 2, \end{cases}\)如果对任意的\(n∈N^{*}\),定义\(f_{n}(x)=\),那么\(f_{2\;016}(2)\)的值为\((\)  \()\)

              A.\(0\)                                               
              B.\(1\)

              C.\(2\)                                                
              D.\(3\)
            • 4.

              已知集合\(A=\{y|y={{x}^{2}}+1\}\),\(B=\{x|y=\sqrt{x}+2\}\),则\(A∩B= \)

              A.\([0,+\infty )\)
              B.\((0,1]\)
              C.\([0,1)\)
              D.\([1,+\infty ) \)
            • 5.

              函数\(f(x)= \sqrt{2^{x}-1}+ \dfrac{1}{x-2}\)的定义域为\((\)  \()\)

              A.\([0,2)\)                                                                  
              B.\((2,+∞)\)

              C.\([0,2)∪(2,+∞)\)                                                
              D.\((-∞,2)∪(2,+∞)\)
            • 6.
              函数\(f(x)= \sqrt {x+1}- \dfrac {1}{2-x}\)的定义域为\((\)  \()\)
              A.\([-1,2)∪(2,+∞)\)
              B.\((-1,+∞)\)
              C.\([-1,2)\)
              D.\([-1,∞)\)
            • 7. 已知函数\(f(x)=\begin{cases}x\;\;\;(x\geqslant 0)\;, \\ {x}^{2}\;\;(x < 0)\;,\end{cases} \)则\(f(f(-2))=\)________.
            • 8.

              已知函数\(f\left( x \right)=\left( {{m}^{2}}-m-1 \right){{x}^{4{{m}^{9}}-{{m}^{5}}-1}}\)是幂函数,对任意的\({{x}_{1}},{{x}_{2}}\in \left( 0,+\infty \right)\),且\({{x}_{1}}\ne {{x}_{2}}\),\(\left( {{x}_{1}}-{{x}_{2}} \right)\left[ f\left( {{x}_{1}} \right)-f\left( {{x}_{2}} \right) \right] > 0\),若\(a,b\in R\),且\(a+b > 0,ab < 0\),则\(f\left( a \right)+f\left( b \right)\)的值\((\)  \()\)

              A.恒大于\(0\)   
              B.恒小于\(0\)   
              C.等于\(0\)   
              D.无法判断
            • 9.

              已知函数 \(f\)\(( \)\(x\)\()=3-2\log _{2}\) \(x\)\(g\)\(( \)\(x\)\()=\log _{2}\) \(x\)

              \((1)\)当\(x\)\(∈[1,4]\)时,求函数\(h\)\((\)\(x\)\()=[\)\(f\)\((\)\(x\)\()+1]·\)\(g\)\((\)\(x\)\()\)的值域;

              \((2)\)如果对任意的\(x\)\(∈[1,4]\),不等式\(f\)\((\)\(x\)\({\,\!}^{2})·\)\(f\)\(( \sqrt{x} ) > \)\(k\)\(·\)\(g\)\((\)\(x\)\()\)恒成立,求实数\(k\)的取值范围.

            • 10.

              定义在\(R\)上的奇函数\(f(x)\)和定义在\(\left\{ x\left| x\ne 0 \right. \right\}\)上的偶函数\(g(x)\)分别满足\(f(x)=\begin{cases} & {{2}^{x}}-1(0\leqslant x < 1) \\ & \dfrac{1}{x}(x\geqslant 1) \end{cases}\),\(g(x)={{\log }_{2}}x(x > 0)\),若存在实数\(a\),使得\(f(a)=g(b)\)成立,则实数\(b\)的取值范围是(    )

              A. \(\left[ -2,2 \right]\)
              B.\([-2,-\dfrac{1}{2}]\cup [\dfrac{1}{2},2]\)
              C.\([-\dfrac{1}{2},0)\cup (0,\dfrac{1}{2}]\)
              D.\(\left( -\infty ,-2 \right]\cup \left[ 2,+\infty \right)\)
            0/40

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