共50条信息
\(17.\)已知集合.
\((1)\)求;
\((2)\)
设全集\(U=R,A=\left\{ x\left| {{x}^{2}}-x-6\geqslant 0 \right. \right\},B=\left\{ x\left| x > 1 \right. \right\}\),则\(({C}_{U}A)∪B= (\) \()\)
函数\(f(x)=\sqrt{|x+1|+|x+2|-a}\).
\((1)\)若\(a=5\),求函数\(f(x)\)的定义域\(A\);
\((2)\)设\(B=\{x|-1 < x < 2\}\),当实数\(a,b\in (B\cap {{C}_{R}}A)\)时,证明:\(\dfrac{|a+b|}{2} < \left| 1+\dfrac{ab}{4} \right|\)
已知集合\(P=\{x|x^{2}-8x-20\leqslant 0\}\),\(S=\{x||x-1|\leqslant m\}\).
\((1)\)若\((P∪S)⊆P\),求实数\(m\)的取值范围;
\((2)\)是否存在实数\(m\),使“\(x∈P\)”是“\(x∈S\)”的充要条件?若存在,求出\(m\)的取值范围;若不存在,请说明理由.
已知集合\(A=\left\{x|\left|x-1\right|\leqslant 2\right\} \),集合\(B=\left\{x|{\log }_{ \frac{1}{2}}x > 1\right\} \)
\((I)\)求\(A∪B \)
\((II)\)求\({C}_{R}\left(A∩B\right) \)
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