优优班--学霸训练营 > 知识点挑题
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            • 1.

              已知\(b > a > 0,\)且\(a+b=1\),那么(    )

              A.\(2ab < \dfrac{{{a}^{4}}-{{b}^{4}}}{a-b} < \dfrac{a+b}{2} < b\)
              B.\(2ab < \dfrac{a+b}{2} < \dfrac{{{a}^{4}}-{{b}^{4}}}{a-b} < b\)
              C.\(\dfrac{{{a}^{4}}-{{b}^{4}}}{a-b} < 2ab < \dfrac{a+b}{2} < b\)
              D.\(2ab < \dfrac{a+b}{2} < b < \dfrac{{{a}^{4}}-{{b}^{4}}}{a-b}\)
            • 2. \(7\)、已知 \(f\)\(( \)\(x\)\()=\) \(x\)\({\,\!}^{2}-\cos \) \(x\),则 \(f\)\((0.6)\), \(f\)\((0)\), \(f\)\((-0.5)\)的大小关系是 \((\)  \()\)
              A.\(f\)\((0) < \) \(f\)\((0.6) < \) \(f\)\((-0.5)\)     
              B.\(f\)\((0) < \) \(f\)\((-0.5) < \) \(f\)\((0.6)\)
              C.\(f\)\((0.6) < \) \(f\)\((-0.5) < \) \(f\)\((0)\)     
              D.\(f\)\((-0.5) < \) \(f\)\((0) < \) \(f\)\((0.6)\)
            • 3. 已知函数\(f(x){=}\dfrac{a{⋅}2^{x}{+}b{+}1}{2^{x}{+}1}\)是定义域在\(R\)上的奇函数,且\(f(2){=}\dfrac{6}{5}\).
              \((1)\)求实数\(a\)、\(b\)的值;
              \((2)\)判断函数\(f(x)\)的单调性,并用定义证明;
              \((3)\)解不等式:\(f(\log{{ }}_{\frac{1}{2}}(2x{-}2){]+}f{[}\log_{2}(1{-}\dfrac{1}{2}x){]\geqslant }0\).
            • 4. 若\(a=0.2^{m}\),\(b=0.2^{n}\),且\(m > n\),则\(a\),\(b\)大小关系为\((\)  \()\)
              A.\(a > b\)
              B.\(a < b\)
              C.\(a=b\)
              D.无法判断大小
            • 5.

              已知实数\(a=1.7^{0.3}\),\(b=0.9^{0.1}\),\(c=\log _{2}5\),\(d=\log _{0.3}1.8\),那么它们的大小关系是

              A.\(c > a > b > d\)   
              B.\(a > b > c > d\)
              C.\(c > b > a > d\)   
              D.\(c > a > d > b\)
            • 6.

              已知定义在\(R\)上的函数\(y=f(x)\)满足:函数\(y=f(x-1)\)的图象关于直线\(x=1\)对称,且当\(x\in (-\infty ,0)\)时,\(f(x)+x{f}{{{"}}}(x) > 0\)恒成立,若\(a=(\sin \dfrac{1}{2})f(\sin \dfrac{1}{2})\),\(b=(\ln 2)f(\ln 2)\),\(c=2f({{\log }_{\frac{1}{2}}}\dfrac{1}{4})\),则\(a,b,c\)的大小关系是\((\)    \()\)

              A.\(c > a > b\)
              B.\(b > a > c\)
              C.\(a > b > c\)
              D.\(a > c > b\) 
            • 7.

              某班的数学爱好者对等比数列\(\left\{ {{3}^{n-1}} \right\}(n\in {{N}^{*}})\)进行深入研究,发现了一些有趣的性质,比如,该数列中任何一项都是奇数,但任何连续两项之和都是\(4\)的倍数;等。讨论由该数列的前\(100\)项组成的集合\(\prod =\left\{ {{a}_{1}},{{a}_{2}},...,{{a}_{100}} \right\}\),由集合\(\prod \)任意选取一些元素,构成其的非空子集\(A\),定义\({{S}_{A}}\)表示集合\(A\)中所有元素之和\((\)如\(A=\left\{ {{a}_{2}},{{a}_{5}} \right\}\),则\({{S}_{A}}=3+{{3}^{4}}=84)\),则对任意的\(A\subset \prod \),都有\({{S}_{A}} < {{3}^{100}}\)。现假设非空集合\(C,D\)都是集合\(\prod \)的真子集,且满足\({{S}_{C}}\geqslant {{S}_{D}}\),则关于\({{S}_{C}}+{{S}_{C\bigcap D}}\)与\(2{{S}_{D}}\)的大小比较中,下列说法最准确的是(    )

              A.\({{S}_{C}}+{{S}_{C\bigcap D}} > 2{{S}_{D}}\)
              B.\({{S}_{C}}+{{S}_{C\bigcap D}}=2{{S}_{D}}\)   
              C.\({{S}_{C}}+{{S}_{C\bigcap D}}\geqslant 2{{S}_{D}}\)
              D.\({{S}_{C}}+{{S}_{C\bigcap D}}\geqslant 2{{S}_{D}}+1\)
            • 8.

              已知实数\(a=\log _{2}3\),\(b={( \dfrac{1}{3})}^{2} \),\(c={\log }_{ \frac{1}{3}} \dfrac{1}{30} \),则\(a\),\(b\),\(c\)的大小关系是\((\)   \()\)

              A.\(a > b > c\)
              B.\(a > c > b\)
              C.\(c > a > b\)
              D.\(c > b > a\)
            • 9.

              \(xyz\)为正数,且\({{2}^{x}}={{3}^{y}}={{5}^{z}}\),则

              A.\(2\) \(x\)\( < 3\) \(y\)\( < 5\) \(z\)
              B.\(5\) \(z\)\( < 2\) \(x\)\( < 3\) \(y\)
              C.\(3\) \(y\)\( < 5\) \(z\)\( < 2\) \(x\)
              D.\(3\) \(y\)\( < 2\) \(x\)\( < 5\) \(z\)
            • 10.

              设\(a=\lg 0.2\),\(b={\log }_{3}2 \),\(c={5}^{ \frac{1}{2}} \),则(    )

              A.\(a < b < c \)
              B.\(b < c < a \)
              C.\(c < a < b \)
              D.\(c < b < a \)
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