优优班--学霸训练营 > 知识点挑题
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            • 1.
              已知函数\(f(x)=|2x+a|-|2x+3|\),\(g(x)=|x-1|-3\).
              \((1)\)解不等式:\(|g(x)| < 2\);
              \((2)\)若对任意的\(x_{1}∈R\),都有\(x_{2}∈R\),使得\(f(x_{1})=g(x_{2})\)成立,求实数\(a\)的取值范围.
            • 2.
              已知函数\(f(x)=|x-5|-|x-2|\).
              \((1)\)若\(∃x∈R\),使得\(f(x)\leqslant m\)成立,求\(m\)的范围;
              \((2)\)求不等式\(x^{2}-8x+15+f(x) < 0\)的解集.
            • 3.
              若关于\(x\)的不等式\(xe^{x}-ax+a < 0\)的解集为\((m,n)(n < 0)\),且\((m,n)\)中只有一个整数,则实数\(a\)的取值范围是\((\)  \()\)
              A.\([ \dfrac {1}{e^{2}}, \dfrac {1}{e})\)
              B.\([ \dfrac {2}{3e^{2}}, \dfrac {1}{2e})\)
              C.\([ \dfrac {1}{e^{2}}, \dfrac {2}{e})\)
              D.\([ \dfrac {2}{3e^{2}}, \dfrac {1}{e})\)
            • 4.
              定义在\(R\)上的函数\(f(x)\)满足\(f(x+2)= \dfrac {1}{2}f(x)\),当\(x∈[0,2)\)时,\(f(x)= \begin{cases} \dfrac {1}{2}-2x^{2},0\leqslant x < 1 \\ -2^{1-|x- \frac {3}{2}|},1\leqslant x < 2\end{cases}\),函数\(g(x)=x^{3}+3x^{2}+m.\)若\(∀s∈[-4,-2)\),\(∃t∈[-4,-2)\),不等式\(f(s)-g(t)\geqslant 0\)成立,则实数\(m\)的取值范围是\((\)  \()\)
              A.\((-∞,-12]\)
              B.\((-∞,-4]\)
              C.\((-∞,8]\)
              D.\((-∞, \dfrac {31}{2}]\)
            • 5.
              不等式\(x^{2}-|x|-2 < 0(x∈R)\)的解集是\((\)  \()\)
              A.\(\{x|x < -1\)或\(x > 1\}\)
              B.\(\{x|x < -2\)或\(x > 2\}\)
              C.\(\{x|-1 < x < 1\}\)
              D.\(\{x|-2 < x < 2\}\)
            • 6.
              已知\(|2x-3|\leqslant 1\)的解集为\([m,n]\),则\(m+n\)的值为 ______ .
            • 7.
              已知函数\(f(x)(x∈R)\)满足\(f(1)=1\),且\(f′(x) < \dfrac {1}{2}\),则\(f(x) < \dfrac {x}{2}+ \dfrac {1}{2}\)的解集为\((\)  \()\)
              A.\(\{x|-1 < x < 1\}\)
              B.\(\{x|x > -1\}\)
              C.\(\{x|x < -1\)或\(x > 1\}\)
              D.\(\{x|x > 1\}\)
            • 8.
              若不等式\((a^{2}-3a-4)x^{2}-(a-4)x-1 < 0\)的解集为\(R\),则实数\(a\)的取值范围为\((\)  \()\)
              A.\((0,4)\)
              B.\((0,4]\)
              C.\([0,4)\)
              D.\([0,4]\)
            • 9.
              已知数列\(\{a_{n}\}\)中\(a_{1}=1\),\(a_{2}=2\),当整数\(n > 1\)时,\(S_{n+1}+S_{n-1}=2(S_{n}+S_{1})\)都成立,则\(S_{15}=\) ______ .
            • 10.
              不等式\( \dfrac {1}{x}\leqslant 1\)的解集为 ______ .
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