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dsProject/dsLightRag/output/数学OCR整理后的结果.md

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第1题

题目内容
已知集合 A=\left\{x \mid -5 < x^{3} < 5\right\}B=\left\{-3,-1,0,2,3\right\},则 A \cap B=

选项
A. \{-1,0\}
B. \{2,3\}
C. \{-3,-1,0\}
D. \{-1,0,2\}

答案A

解析
A \cap B=\{-1,0\},选 A。


第2题

题目内容
\frac{2}{z-1}=1+i,则 z=

选项
A. -1-i
B. -1+i
C. 1-i
D. 1+i

答案C

解析
暂无解析。


第3题

题目内容
已知向量 \vec{a}=(0,1)\vec{b}=(2,x),若 \vec{b} \perp (\vec{b}-4\vec{a}),则 x=

选项
A. -2
B. -1
C. 1
D. 2

答案D

解析
\vec{b}-4\vec{a}=(2,x-4)\vec{b} \perp (\vec{b}-4\vec{a})\therefore \vec{b}(\vec{b}-4\vec{a})=0

\therefore 4+x(x-4)=0\therefore x=2,选 D。


第4题

题目内容
已知 \cos(\alpha+\beta)=m\tan \alpha \tan \beta=2,则 \cos(\alpha-\beta)=

选项
A. -3m
B. -\frac{m}{3}
C. \frac{m}{3}
D. 3m

答案A

解析
\left\{\begin{array}{l}\cos \alpha \cos \beta-\sin \alpha \sin \beta=m \\\frac{\sin \alpha \sin \beta}{\cos \alpha \cos \beta}=2\end{array}\right.\therefore \left\{\begin{array}{l}\sin \alpha \sin \beta=-2m \\\cos \alpha \cos \beta=-m\end{array}\right.

\cos(\alpha-\beta)=\cos \alpha \cos \beta+\sin \alpha \sin \beta=-m-2m=-3m,选 A。


第5题

题目内容
已知圆柱和圆锥的底面半径相等,侧面积相等,且它们的高均为 \sqrt{3},则圆锥的体积为

选项
A. 2\sqrt{3}\pi
B. 3\sqrt{3}\pi
C. 6\sqrt{3}\pi
D. 9\sqrt{3}\pi

答案B

解析
设它们底面半径为 r,圆锥母线 l\therefore 2\pi r\sqrt{3}=\pi rl\therefore l=\sqrt{3},则圆锥的体积为 \frac{1}{3}\pi r^{2}h