This repository has been archived on 2024-06-23. You can view files and clone it, but cannot push or open issues or pull requests.
mathdeptv2/工具v4/文本文件/metadata.txt

707 lines
9.1 KiB
Plaintext
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

ans
024871
B
024872
A
024873
D
024874
$[\dfrac{1}{2},1]$
024875
$[-1,0)\cup (3,4)$
024876
$\{(2,3)\}$
024877
D
024878
A
024879
D
024880
$3$
024881
$a\le \dfrac{1}{3}$
024882
$a\ge \dfrac{1}{5}$
024883
$\{a_2,a_4\}$, $\{a_1,a_2,a_4\}$, $\{a_2,a_3,a_4\}$, $\{a_1,a_2,a_3,a_4\}$
024884
$\{0,1\}$
024885
$(-\infty,-1]\cup \{1\}$
024886
\textcircled{4}
024887
B
024888
C
024889
充分非必要条件, 理由略
024890
(1) 证明略; (2) 证明略
024891
(1) $(1,+\infty)$; (2) $[-3,1]$
024892
$-3b^2$
024893
$1.82$
024894
$3$或$\dfrac{1}{3}$
024895
$(1,5)$
024896
$-1$
024897
$(-\infty,2]$
024898
$\dfrac{5}{2}$
024899
$2$
024900
$(2,5)$
024901
$3$
024902
C
024903
$[-6,1]$
024904
(1) $f(x)=\begin{cases}
\log_2 \dfrac{1}{x}, & x>0, \\ 0, & x=0, \\ -\log_2(-\dfrac{1}{x}), & x<0;
\end{cases}$ (2) 解集为$(-\log_2 3,+\infty)$
024905
(1) $(-\infty,-1]\cup [3,+\infty)$; (2) $(-\infty,3]$
024906
(1) $(-\infty,-\dfrac{3}{4}]$; (2) $\sqrt{3}$
024907
$-\dfrac{27}{19}$
024908
B
024909
$(1,\dfrac{3}{2}]$
024910
(1) $y=\begin{cases}
4t, & 0\le t<1, \\ (\dfrac{1}{2})^{t-3}, & t\ge 1;
\end{cases}$ (2) $\dfrac{79}{16}$
024911
$[\dfrac{1}{2},\dfrac{7}{2}]$
024912
(1) 证明略; (2) $(1,\dfrac{3}{2}]\cup \{2,3\}$
024913
D
024914
B
024915
C
024916
$\dfrac{1}{100}$
024917
$2$
024918
C
024919
A
024920
D
024921
C
024922
$(0,1]$
024923
$5$
024924
B
024925
$(-\infty,2]$
024926
(1) \begin{tikzpicture}[>=latex, scale = 0.6]
\draw [->] (-4,0) -- (4,0) node [below] {$x$};
\draw [->] (0,-5) -- (0,5) node [left] {$y$};
\draw (0,0) node [above left] {$O$};
\draw (-2,0) node [below left] {$-2$} (2,0) node [below right] {$2$} (0,-2) node [above right] {$-2$} (0,2) node [below right] {$2$} (0,4) node [below right] {$4$};
\foreach \i in {-5,-4,-3,-2,-1,1,2,3,4,5}
{\draw [dashed] (-4,\i) -- (4,\i);};
\foreach \i in {-4,-3,-2,-1,1,2,3,4}
{\draw [dashed] (\i,-5) -- (\i,5);};
\draw [domain = {-1-sqrt(6)}:0, samples = 100] plot (\x,{\x*(\x+2)});
\draw [domain = 0:{1+sqrt(6)}, samples = 100] plot (\x,{-\x*(\x-2)});
\end{tikzpicture} (2) $f(x)=-x^2+2x$($x>0$); (3) $(-1,1)$
024927
$(1,+\infty)$
024928
C
024929
C
024930
$-4$; $8$
024931
(1) $k=1$; (2) $Q(x)=125-|x-25|$($1\le x\le 30$, $x\in \mathbf{N}$); (3) $121$
024932
$(\dfrac{1}{3},-\dfrac{29}{27})$
024933
$0$; $(0,2)$
025063
B
025064
$\dfrac{2\sqrt{2}}{3}$
025065
$5$
025066
$-\dfrac{23}{16}$
025067
C
025068
B
025069
$-\dfrac{60}{169}$; $-\dfrac{12}{5}$
025070
$\dfrac{1}{3}$
025071
$\dfrac{7}{25}$
025072
B
025073
A
025074
D
025075
存在, $\alpha=\dfrac{\pi}{4}$, $\beta=\dfrac{\pi}{6}$
013851
(1) $28.28$米; (2) $26.93$米
025076
\textcircled{1}\textcircled{3}
025077
\textcircled{1}\textcircled{2}\textcircled{4}
025078
若选择\textcircled{1}, $a=8$, $b=3$; 若选择\textcircled{2}, $a=6$, $b=5$
025079
$2+\dfrac{3\sqrt{2}}{2}$
025080
C
025081
(1) $\sqrt{6}+\sqrt{2}$; (2) 证明略; (3) 当$a>2R$或$a=b=2R$时, $\triangle ABC$不存在; 当$b<a=2R$时, $\triangle ABC$有且仅有一个, $c=\sqrt{a^2-b^2}$; 当$b=a<2R$时, $\triangle ABC$有且仅有一个, $c=\dfrac{a}{R}\sqrt{4R^2-a^2}$; 当$b<a<2R$时, $\triangle ABC$有且仅有两个, $c=\sqrt{a^2+b^2\pm \dfrac{ab}{2R^2}(\sqrt{4R^2-a^2}\cdot \sqrt{4R^2-b^2}-ab)}$
024934
B
024935
D
024936
C
024937
B
024938
B
024939
$\dfrac{\sqrt{3}}{3}$
024940
$\dfrac{5\pi}{6}$
024941
C
024942
D
024943
B
024944
\textcircled{1}\textcircled{2}
024945
$\dfrac{\pi}{2}$
024946
(1) $\dfrac{\pi}{2}$; (2) 最大值为$3$, 当且仅当$x=\dfrac{\pi}{6}$时取到最大值; 最小值为$0$, 当且仅当$x=-\dfrac{\pi}{6}$时取到最小值
024947
(1) $[-\dfrac{\pi}{6},\dfrac{\pi}{3}]$和$[\dfrac{5\pi}{6},\pi]$; (2) 当$-2<a<-1$时, 方程无根; 当$-1<a\le 0$时, 方程有三个根; 当$a=-1$或$0<a<1$时, 方程有两个根
024948
(1) $[k\pi,k\pi+\dfrac{\pi}{2}]$, $k\in \mathbf{Z}$; (2) $-\dfrac{\sqrt{3}}{4}$
024949
\textcircled{2}\textcircled{3}\textcircled{4}
024950
D
024951
B
024952
(1) $\theta=\dfrac{\pi}{6}$, $\omega = 2$; (2) $x_0=\dfrac{2\pi}{3}$或$\dfrac{3\pi}{4}$
024953
(1) 存在$a=1$满足条件\textcircled{2}\textcircled{3}; (2) $(\dfrac{3\pi}{8},\dfrac{7\pi}{8}]$
024954
D
024955
D
024956
\textcircled{1}\textcircled{3}\textcircled{4}
024957
$\overrightarrow{AB}$
024958
$-\dfrac{5}{2}$
024959
$\dfrac{2\pi}{3}$
024960
C
024961
C
024962
D
024963
A
024964
B
024965
\begin{tikzpicture}[>=latex]
\draw (0,0) node [below right] {$A$} coordinate (A);
\draw (-1,0) node [below] {$B$} coordinate (B);
\draw (B) ++ (130:2) node [above] {$C$} coordinate (C);
\draw (C) ++ (1,0) node [above] {$D$} coordinate (D);
\draw (-2,0) node [below] {西} coordinate (l) -- (-1,0);
\draw [->] (0,0) -- (1,0) node [below] {东};
\draw [->] (0,-1) node [right] {南} -- (0,2) node [right] {北};
\draw (B) pic [draw, "$50^\circ$", scale = 0.5, angle eccentricity = 2.5] {angle = C--B--l};
\draw [->] (A)--(B);
\draw [->] (B)--(C);
\draw [->] (C)--(D);
\draw [->] (A)--(D);
\end{tikzpicture}
024966
(1) $\dfrac{1}{3}$; (2) $(-\dfrac{1}{2},\dfrac{1}{2})$
024967
(1) $(\sqrt{10},-2\sqrt{2})$或$(-\sqrt{10},2\sqrt{2})$; (2) $\dfrac{39}{8}$
024968
$14$; $10$
024969
$\dfrac{4}{3}$
024970
A
024971
(1) $\sqrt{3}$, $\dfrac{\sqrt{7}}{2}$; (2) 是定值$\dfrac{7}{8}$
032864
$\sqrt{7}$
024972
A
024973
D
024974
B
024975
D
024976
C
024977
B
024978
\textcircled{1}\textcircled{4}
024979
$\sqrt{2}$
024980
$-1$
024981
$\pm 4$
024982
B
024983
$5\sqrt{2}$; 一
024984
(1) $\dfrac{1}{2}$; (2) $(-\infty,-\dfrac{3}{2})$
024985
$-\dfrac{5}{3}$或$\dfrac{\sqrt{14}}{2}$
040763
$(x+y)(x-y)(x+y\mathrm{i})(x-y\mathrm{i})$
040764
$\dfrac{1}{12}$
024986
\textcircled{4}
024987
$\dfrac{3}{5}$或$\dfrac{5}{3}$或$-1$
024988
A
024989
$(-\infty,2-2\sqrt{2})\cup (2+\sqrt{2},+\infty)$
024990
$-10102$
024991
$(\dfrac{5}{4},\dfrac{10}{7}]$
024992
$-360$
024993
$68$
024994
$\begin{cases}
6n-1, & n\ge 2,\\ 6, & n=1
\end{cases}$
024995
$16$
024996
D
024997
$7$
024998
$\dfrac{3}{4}(9^n-1)$
024999
$\dfrac{4}{3}$
025000
$3^n-2$
025001
$-\dfrac{1}{2021}$
025002
(1) $a_n=\begin{cases}
\dfrac{1}{2}, & n=1, \\ 4, & n\ge 2;
\end{cases}$ (2) $T_n=2^{\frac{n(n-1)}{2}}$($n\in \mathbf{N}$, $n\ge 1$)
025003
有最大项, 最大项为$\dfrac{10^{10}}{11^9}$, 序数为$9$或$10$
025004
证明略
025005
B
025006
D
025007
(1) 证明略; (2) $(-\infty,-\dfrac{1}{3}]\cup [3,+\infty)$
025008
D
025009
$(-2,4)$
025010
$-6$
025011
$4$
025012
$\dfrac{1}{2}$
025013
$-\dfrac{\sqrt{3}}{3}$
025014
$2$
025015
$y=x-2$
025016
$4$
025017
$\dfrac{7\sqrt[8]{x^7}}{8x}$, $2\cos 2x$, $\dfrac{\mathrm{e}^x(x-1)}{x^2}$, $-\dfrac{1}{\sin^2 x}$, $\dfrac{2}{2x+1}-\mathrm{e}^{-x}(\cos 2x+2\sin 2x)$
025018
$-1$
025019
$[3,+\infty)$
025020
$(-\infty,0]\cup [3,+\infty)$
025021
$(-\dfrac{4}{3},\dfrac{28}{3})$
025022
$7.2$元, $20\mathrm{km}/\mathrm{h}$
025023
(1) $y=-4x+5$; (2) 在$(-\infty,-1]$和$[4,+\infty)$上严格增, 在$[-1,4]$上严格减, 最大值为$1$, 最小值为$-\dfrac{1}{4}$
025024
\textcircled{2}\textcircled{3}\textcircled{4}
025025
(1) $f'(x)=a\mathrm{e}^x\ln x+\dfrac{a\mathrm{e}^x}{x}+\dfrac{b\mathrm{e}^{x-1}x-b\mathrm{e}^{x-1}}{x^2}$; (2) $a=1$, $b=2$
025026
$1$
025027
$(-10,-2)$
025028
D
025029
(1) 最小值为$-\dfrac{1}{\mathrm{e}}$, 最大值为$0$; (2) $[1,+\infty)$
025030
$1$
025031
$\dfrac{1}{2}$
025032
$-\sqrt{3}$
025033
$[\dfrac{\pi}{12},\dfrac{\pi}{2}]$
025034
$2-\ln 2$
025035
$-6$
025036
$2$
025037
$\sqrt{3}$
025038
$\dfrac{\pi}{3}$
025039
C
025040
A
025041
B
025042
(1) $m=-4$, $n=5$; (2) $2\sqrt{3}$
025043
(1) $\pi-\arccos\dfrac{7\sqrt{19}}{38}$; (2) $(-\infty,-6)\cup (-6,\dfrac{7}{2})$
025044
(1) $AC=100\sqrt{7}$米, 原花园建筑用地$ABCD$的面积为$20000\sqrt{3}$平方米; (2) 当$\triangle ACP$为正三角形时, 新建筑用地面积最大, 最大值为$22500\sqrt{3}$平方米
019882
(1) $2$; (2) 定值为$6$, 证明略; (3) 存在, 最小值为$-2$
025045
(1) 极小值为$2-2\ln 2$, 无极大值; (2) 当$-2<a<0$时, 在$(0,\dfrac{1}{2}]$和$[-\dfrac{1}{a},+\infty)$上严格减, 在$[\dfrac{1}{2},-\dfrac{1}{a}]$上严格增; 当$a=-2$时, 在$(0,+\infty)$上严格减; 当$a<-2$时, 在$(0,-\dfrac{1}{a}]$和$[\dfrac{1}{2},+\infty)$上严格减, 在$[-\dfrac{1}{a},\dfrac{1}{2}]$上严格增; (3) $(-\infty,-\dfrac{13}{3}]$
025046
$\dfrac{\pi}{6}$
025047
$y=-x^{-2}$
025048
$-\dfrac{2\sqrt{6}}{5}$
011606
$2\sqrt{6}$
025049
$15$
025050
$y=-x+2$
025051
$\pi-\arccos\dfrac{1}{6}$
025052
$-2$
025053
\textcircled{1}
025054
$(-\dfrac{1}{\mathrm{e}},-0.02\ln 10)$
025055
$\dfrac{\sqrt{15}}{2}$
025056
C
025057
B
025058
A
014338
$(39,13)$
025059
(1) $f(x)=2\sin (2x+\dfrac{\pi}{3})$, 最小正周期为$\pi$; (2) $[-1,2]$
025060
(1) $\dfrac{100}{9}$; (2) $\dfrac{100}{7}$
025061
(1) $(0,\dfrac{1}{2}]$和$[2,+\infty)$; (2) $(-\infty,0)\cup \{1\}$; (3) 当$a=1$时, $f(x)$在$(0,+\infty)$上严格增; 当$a\in (0,1)$时, $f(x)$在$(0,a]$和$[\dfrac{1}{a},+\infty)$`上严格增, 在$(a,\dfrac{1}{a})$上严格减
025062
(1) 在$(0,+\infty)$上严格增; (2) $(-\infty,2+\dfrac{3}{\mathrm{e}}]$
025082
$\begin{cases}
1 & n=1,\\ -3, & n\ge 2
\end{cases}$
025083
B
025084
C
025085
(1) $\sqrt{26}$; (2) $-\dfrac{8}{13}$
025086
(1) 在$(0,+\infty)$上严格增; (2) $(\dfrac{5}{2},+\infty)$; (3) $[8-5\ln 2,+\infty)$