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mathdeptv2/工具/文本文件/metadata.txt

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021441
错误, 正确, 错误, 错误
021442
D
021443
C
021444
A
021445
C
021446
D
021447
$-390^\circ$
021448
$304^\circ$, $-56^\circ$
021449
$-144^\circ$
021450
二, 四
021451
(1) $\{\alpha|\alpha=60^\circ+k\cdot 360^\circ, \ k\in \mathbf{Z}\}$, $-300^\circ$, $60^\circ$, $420^\circ$; (2) $\{\alpha|\alpha = -21^\circ+k\cdot 360^\circ, \ k \in \mathbf{Z}\}$, $-21^\circ$, $339^\circ$, $699^\circ$
021452
\begin{tikzpicture}[>=latex]
\fill [pattern = north east lines] (30:2) arc (30:60:2) -- (0,0) -- cycle;
\draw (30:2) -- (0,0) -- (60:2);
\draw [->] (-2,0) -- (2,0) node [below] {$x$};
\draw [->] (0,-2) -- (0,2) node [left] {$y$};
\draw (0,0) node [below left] {$O$};
\end{tikzpicture}
021453
$-1290^{\circ}$;第二象限
021454
(1) $ \{\alpha|\alpha=45^{\circ}+k\cdot 360^{\circ}, \ k \in \mathbf{Z}\}$;\\
(2) $\{\alpha|\alpha=135^{\circ}+k\cdot 180^{\circ}, \ k \in \mathbf{Z}\}$;\\
(3) $\{\alpha|\alpha=45^{\circ}+k\cdot 90^{\circ}, \ k \in \mathbf{Z}\}$;\\
(4) $\{\alpha|180^{\circ}+k\cdot 360^{\circ}<\alpha<270^{\circ}+k\cdot 360^{\circ}, \ k \in \mathbf{Z}\}$.
021455
(1) $ \{\beta|\beta=\alpha+180^{\circ}+k\cdot 360^{\circ}, \ k \in \mathbf{Z}\}$;\\
(2) $\{\beta|\beta=\alpha+90^{\circ}+k\cdot 180^{\circ}, \ k \in \mathbf{Z}\}$;\\
(3) $\{\beta|\beta=-\alpha+k\cdot 360^{\circ}, \ k \in \mathbf{Z}\}$;\\
(4) $\{\beta|\beta=90^{\circ}-\alpha+k\cdot 360^{\circ}, \ k \in \mathbf{Z}\}$.
021456
C
021457
B
021458
$\dfrac{\pi}{12}$; $\dfrac{7\pi}{12}$; $\dfrac{5\pi}{4}$; $300^{\circ}$; $324^{\circ}$; $315^{\circ}$; $(\dfrac{270}{\pi})^{\circ}$
021459
(1)$\frac{50\pi+180}{9}$;(2)$\frac{250\pi}{9}$
021460
$\sqrt{3}$
021461
(1)$\frac{\pi}{3}$;(2)$\frac{2\pi}{3}$
021462
(1)$16\pi+\frac{2\pi}{3}$,二;\\
(2)$-18\pi+\frac{4\pi}{3}$,三;\\
(3)$-2\pi+\frac{7\pi}{5}$,三;\\
(4)$-2\pi+\frac{3\pi}{4}$,二.
021463
$\frac{1}{2}$
021464
(1) $\{\alpha|-\frac{\pi}{2}+2k\pi<\alpha<2k\pi,\ k \in \mathbf{Z}\}$;\\
(2) $\{\alpha|\alpha=\frac{k\pi}{2},\ k \in \mathbf{Z}\}$.
021465
(1) $\beta=\alpha+2k\pi,\ k \in \mathbf{Z}$;\\
(2) $\beta=-\alpha+2k\pi,\ k \in \mathbf{Z}$;\\
(3) $\beta=-\alpha+\pi+2k\pi,\ k \in \mathbf{Z}$;\\
(4) $\beta=\alpha+\pi+2k\pi,\ k \in \mathbf{Z}$.
021466
(1) $\{\alpha|-\frac{\pi}{4}+2k\pi \le \alpha \le \frac{\pi}{2}+2k\pi,\ k \in \mathbf{Z}\}$;\\
(2) $\{\alpha|\frac{\pi}{6}+k\pi \le \alpha \le \frac{5\pi}{6}+k\pi,\ k \in \mathbf{Z}\}$.
021467
(1) 第四象限;第四象限;\\
(2) 第二象限或者第四象限;第一象限或第二象限或者$y$轴正半轴.
021468
$A\cap B=\{\alpha | 2k \pi+\dfrac{5\pi}{6}<\alpha<2k \pi+\dfrac{7\pi}{6},\ k \in \mathbf{Z} \}$
021469
\begin{tabular}{|c|c|c|c|c|c|}
\hline &$P(-5,12)$&$P(0,-6)$&$P(6,0)$&$P(-9,-12)$&$P(1,-\sqrt{3})$\\
\hline$\sin \alpha$&$\dfrac{12}{13}$ &$-1$ & $0$&$-\dfrac{4}{5}$ &$-\dfrac{\sqrt{3}}2$ \\
\hline$\cos \alpha$&$-\dfrac{5}{13}$ &$0$ & $1$&$-\dfrac{3}{5}$ &$\dfrac 12$ \\
\hline$\tan \alpha$&$-\dfrac{12}{5}$ &不存在 & $0$&$\dfrac{4}{3}$ &$-\sqrt{3}$ \\
\hline$\cot \alpha$&$-\dfrac{5}{12}$ &$0$ & 不存在 &$\dfrac {3}{4}$ &$-\dfrac{\sqrt{3}}3$ \\
\hline
\end{tabular}
021470
$2\sqrt{5}$
021471
$\frac{2\sqrt{13}}{13}$;$-\frac{2}{3}$
021472
$ \left( -2,\frac{2}{3} \right)$
021473
$<$
021474
5
021475
2
021476
当$t=\sqrt{5}$时, $\cos \alpha=- \frac{\sqrt{6}}{4}$, $\tan \alpha =- \frac{\sqrt{15}}{3}$;\\
当$t=-\sqrt{5}$时, $\cos \alpha=- \frac{\sqrt{6}}{4}$, $\tan \alpha = \frac{\sqrt{15}}{3}$;\\
当$t=0$时, $\cos \alpha=-1$, $\tan \alpha = 0$.
021477
当$\alpha$在第二象限时,$ \sin \alpha =\frac{4}{5}$, $\tan \alpha=-\frac{4}{3}$;\\
当$\alpha$在第三象限时,$ \sin \alpha =-\frac{4}{5}$, $\tan \alpha=\frac{4}{3}$.
021478
$-\frac{\sqrt{3}}{4}$
021479
(1) 第四象限; (2) 第一、四象限;(3)第一、三象限;(4)第一、三象限.
021480
$A=\left\{ -2,-0,4 \right\}$
021481
(1) $\{\alpha|2k\pi \le \alpha \le \frac{\pi}{2}+2k\pi,\ k \in \mathbf{Z}\}$;\\
(2) $[0,3)$
021482
\begin{center}
\begin{tabular}{|c|c|c|c|c|c|}
\hline$\alpha$&$\dfrac{\pi}{3}$&$\dfrac{7 \pi}{4}$&$\dfrac{2021 \pi}{2}$&$-\dfrac{\pi}{6}$&$-\dfrac{22 \pi}{3}$\\
\hline$\sin \alpha$& $\frac{\sqrt{3}}{2}$ &$-\frac{\sqrt{2}}{2}$ & $1$&$-\frac{1}{2}$ &$\frac{\sqrt{3}}{2}$ \\
\hline$\cos \alpha$&$\frac{1}{2}$ &$\frac{\sqrt{2}}{2}$ & $0$&$\frac{\sqrt{3}}{2}$ &$-\frac{1}{2}$ \\
\hline$\tan \alpha$&$\sqrt{3}$ &$-1$ & 不存在 &$-\frac{\sqrt{3}}{3}$ &$-\sqrt{3}$\\
\hline$\cot \alpha$&$\frac{\sqrt{3}}{3}$ &$-1$ & $ 0$&$-\sqrt{3}$ &$-\frac{\sqrt{3}}{3}$ \\
\hline
\end{tabular}
\end{center}
021483
(1) $\{x|x=\frac{4\pi}{3}+2k \pi$或$ x=\frac{5\pi}{3}+2k \pi,\ k \in \mathbf{Z} \}$;\\
(2) $\{-\frac{2\pi}{3},-\frac{\pi}{3},\frac{4\pi}{3} ,\frac{5\pi}{3},\frac{10\pi}{3},\frac{11\pi}{3} \}$
021484
$-\frac{2\sqrt{5}}{5}$;$2$
021485
\textcircled{2} \textcircled{4}
021486
当$\alpha$在第一象限时,$ \sin \alpha =\frac{3\sqrt{10}}{10}$, $\cos \alpha =\frac{\sqrt{10}}{10}$,$\tan \alpha=3$;\\
当$\alpha$在第三象限时,$ \sin \alpha =-\frac{3\sqrt{10}}{10}$,$\cos \alpha =-\frac{\sqrt{10}}{10}$, $\tan \alpha=3$.
021487
$\sin k\pi =0$;\\$\cos k\pi=\left\{
\begin{array}{lc}
$1$, & k=2n \\
$ -1$ , &k=2n-1\\
\end{array}
\right.$ ($n \in \mathbf{Z}$).
021488
(1) $\{\theta | 2k \pi+\dfrac{\pi}{3}<\theta<2k \pi+\dfrac{2\pi}{3},\ k \in \mathbf{Z} \}$;\\
(2) $\{\theta | k \pi-\dfrac{\pi}{2}<\theta \le k \pi-\dfrac{\pi}{6},\ k \in \mathbf{Z} \}$;\\
(3) $\{\theta | k \pi+\dfrac{\pi}{3} \le \theta \le k \pi+\dfrac{2\pi}{3},\ k \in \mathbf{Z} \}$.
021489
第二象限
021490
(1) 当$\dfrac{\alpha}{2}$在第二象限时,点$P$在第四象限;\\
当$\dfrac{\alpha}{2}$在第四象限时,点$P$在第二象限.\\
(2) $\sin (\cos \alpha) \cdot \cos (\sin \alpha)<0$
021491
当$m=0$时,$ \cos (\alpha+1905^{\circ})=-1$,$\tan (\alpha-615^{\circ})=0$;\\
当$m=\sqrt{5}$时,$ \cos (\alpha+1905^{\circ}) =-\frac{\sqrt{6}}{4}$,$\tan (\alpha-615^{\circ})=-\frac{\sqrt{15}}{3}$;\\
当$m=-\sqrt{5}$时,$ \cos (\alpha+1905^{\circ}) =-\frac{\sqrt{6}}{4}$,$\tan (\alpha-615^{\circ})=\frac{\sqrt{15}}{3}$.
021492
$-\dfrac{3}{8}$
021493
$-\dfrac{1}{20}$
021494
$\dfrac{7\sqrt{2}}{4}$
021495
$\dfrac{3\sqrt{5}}{5}$
021496
$11$
021497
$5$;$-\dfrac{12}{5}$;$\dfrac{4}{9}$
021498
$\sin ^2 \alpha$
021499
$1$
021502
$-\dfrac{12}{5}$
021503
$-\dfrac{\sqrt{3}}{2}$
021504
$\dfrac{\sqrt{7}}{2}$;$\dfrac{\sqrt{7}}{4}$
021505
$-\dfrac{\sqrt{11}}{3}$
021506
$\dfrac{\pi}{3}$
021507
$\left[ 0,\pi \right )$
021508
$-\dfrac{\sqrt{3}}{2}$;$-\dfrac{\sqrt{2}}{2}$;$-\sqrt{3}$;$-\sqrt{3}$
021509
$69^{\circ}$;$72^{\circ}$;$\dfrac{\pi}{9}$;$\dfrac{7 \pi}{15}$
021510
$\cot \alpha$
021511
$-1$
021512
$-1$
021513
$ \sin 2-\cos 2$
021514
$0$
021515
$0$
021516
$-\dfrac{\sqrt{1-a^2}}{a}$
021517
$-\dfrac{2+\sqrt{3}}{3}$
021518
(1) $\dfrac{\sqrt{3}}{2}$;(2) $\dfrac{1}{4}$.
021519
(1) $-\dfrac{2}{3}$; \\
(2) $\dfrac{2}{3}$; \\
(3) $-\dfrac{\sqrt{5}}{3}$;\\
(4) $\dfrac{\sqrt{5}}{2}$.
021520
(1) $\sin 69^{\circ}$ ; (2) $-\cos 8^{\circ}$ ;
(3) $-\tan \dfrac{\pi}{9}$; (4) $\cot \dfrac{7\pi}{15}$.
021521
$\dfrac{2}{5}$
021522
$(3,4)$
021523
$0$
021524
$\sin \alpha$
021525
$-\dfrac{1}{5}$
021526
(1) $\dfrac{\sqrt{6}}{6}-\sqrt{3}$;\\
(2) $-\dfrac{\sqrt{6}}{3}$;\\
(3) $1$
021527
(1) $\dfrac{6 \pi}{5}$; (2) $\dfrac{4 \pi}{5}$; (3) $\dfrac{13 \pi}{10}$; (4) $\dfrac{17 \pi}{10}$.
021528
(1) 当$\alpha$在第一象限时, $\sin (2 \pi-\alpha)=-\dfrac{\sqrt{3}}{2}$;
当$\alpha$在第三象限时, $\sin (2 \pi-\alpha)=\dfrac{\sqrt{3}}{2}$.\\
(2) 当$\alpha$在第一象限时, $\dfrac{1}{\tan [\dfrac{(2 k+1) \pi}{2}+\alpha]}=-\sqrt{3}$;
当$\alpha$在第四象限时, $\dfrac{1}{\tan [\dfrac{(2 k+1) \pi}{2}+\alpha]}=\sqrt{3}$.
021529
(1) $\{x | x=k \pi+ (-1)^k \cdot \dfrac{\pi}{4},\ k \in \mathbf{Z}\}$;\\
(2) $\{x | x=2k \pi \pm \dfrac{2\pi}{3},\ k \in \mathbf{Z}\}$;\\
(3) $\{x | x=k \pi + \dfrac{5\pi}{6},\ k \in \mathbf{Z}\}$;\\
(4) $\{x | x=2k \pi + \dfrac{5\pi}{6}$ 或$x=2k \pi + \dfrac{3\pi}{2} ,\ k \in \mathbf{Z}\}$;\\
第二种写法: $\{x | x=k \pi+ (-1)^k \cdot \dfrac{\pi}{6}+\dfrac{2\pi}{3},\ k \in \mathbf{Z}\}$;\\
(5) $\{x | x=k \pi - \arctan \dfrac{\sqrt{3}}{2}+ \dfrac{\pi}{4},\ k \in \mathbf{Z}\}$;\\
(6) $\{x | x=\dfrac{2k \pi}{5} + \dfrac{7\pi}{60}$ 或$ x=\dfrac{2k \pi}{5} - \dfrac{13\pi}{60} ,\ k \in \mathbf{Z}\}$;\\
(7) $\{x | x=k \pi - \dfrac{5\pi}{8}$ 或$x=k \pi - \dfrac{3\pi}{8} ,\ k \in \mathbf{Z}\}$;
021530
(1) $\{ \dfrac{\pi}{12},\dfrac{17\pi}{12} \}$;\\
(2) $\{ \dfrac{5\pi}{6} \}$;\\
(3) $\{ \dfrac{\pi}{12},\dfrac{5\pi}{12} \}$;\\
(4) $\{ \dfrac{5\pi}{6} \}$.
021531
(1) $\{x | x= \dfrac{2k \pi}{5} ,\ k \in \mathbf{Z}\}$;\\
(2) $\{x | x= \dfrac{2k \pi}{3} +\dfrac{ \pi}{6},\ k \in \mathbf{Z}\}$;\\
(3) $\{x | x= 2k \pi$ 或$x=k \pi +(-1)^k \cdot \dfrac{ \pi}{6},\ k \in \mathbf{Z}\}$;\\
(4) $\{x | x= k \pi+\dfrac{ \pi}{3}$ 或$x=k \pi -\dfrac{ \pi}{6},\ k \in \mathbf{Z}\}$.
021532
$\dfrac{3+4\sqrt{3}}{10}$
021533
$-1$
021534
$-\dfrac{33}{50}$
021535
(1) $\dfrac{\sqrt{6}-\sqrt{2}}{4}$;
(2) $\dfrac{\sqrt{6}+\sqrt{2}}{4}$;
(3) $0$.
021536
(1) $\sqrt{3} \sin \alpha$;
(2) $\cos(\alpha-2\beta)$.
021537
$\dfrac{140}{221}$
021538
$\dfrac{2\sqrt{6}-1}{6}$
021540
C
021541
A
021542
$\dfrac{3\sqrt{10}+6\sqrt{2}+2\sqrt{14}-\sqrt{70}}{24}$
021543
$\dfrac{8\sqrt{3}-21}{20}$
021544
$\dfrac{\pi}{2}$
040018
(1) $\dfrac{\pi}{4}$; (2) $\dfrac{\pi}{6}$; (3) $\dfrac{\pi}{10}$; (4) $\dfrac{\pi}{3}$; (5) $\dfrac{5\pi}{12}$; (6) $\dfrac{\pi}{15}$
040019
(1) $60^{\circ}$; (2) $36^{\circ}$; (3) $45^{\circ}$; (4) $75^{\circ}$; (5) $40^{\circ}$; (6) $54^{\circ}$
040020
(1) $2k\pi+\dfrac{\pi}{2}$; (2) $2k\pi+\dfrac{3\pi}{2}$; (3) $2k\pi+\dfrac{7\pi}{6}$; (4) $k\pi+\dfrac{\pi}{4}$; (5) $\dfrac{k\pi}{2}+\dfrac{\pi}{6}$
040021
(1) $k \times 360^{\circ}+60^{\circ}$;\\
(2) $k \times 360^{\circ}+330^{\circ}$; \\
(3) $k \times 360^{\circ}-210^{\circ}$; \\
(4) $k \times 180^{\circ}-45^{\circ}$; \\
(5) $k \times 90^{\circ}+50^{\circ}$
040022
(1) $330^{\circ}$; (2) $240^{\circ}$; (3) $210^{\circ}$; (4) $300^{\circ}$
040023
(1) $\dfrac{4\pi}{3}$; (2) $\dfrac{11\pi}{6}$; (3) $10-2\pi$; (4) $-10+4\pi$
040024
$18$
040025
$3$,$-2$
040026
(1) $1037$; (2) $-4k+53$; (3) $500$
040027
$-2n+10$
040028
15
040029
$7$
040030
$(4,\dfrac{14}{3}]$
040031
$2n-1$
040032
$(3,\dfrac{35}{9})$或$(\dfrac{35}{9},3)$
040033
$200$
040034
040035
$a_n=\begin{cases}1, & n=1,\\ 2n, & n=2k, \\ 2n-2, & n=2k+1\end{cases}$($k\in \mathbf{N}$, $k\ge 1$)
040036
$6n-3$
040057
$\dfrac{19}{28}\sqrt{7}$
040058
$\dfrac{79}{156}$
040059
$2$
040060
$-\dfrac{\sqrt{1-m^2}}{m}$
040061
$-\dfrac{1}{5}, \dfrac{1}{5}$
040062
$-\dfrac{1}{3}, 3$
040063
$\dfrac{1}{2}, -2$
040064
$\dfrac{\sqrt{6}}{3}$
040065
$\dfrac{1}{3}, -\dfrac{9}{4}$
040066
$\dfrac{1}{3}, \dfrac{7}{9}$
040067
$\pm\dfrac{\sqrt{2}}{3}$
040068
$\dfrac{1}{4}, \dfrac{2}{5}$
040069
$\dfrac{1-\sqrt{17}}{4}$
040070
(1) 三; (2) 三
040071
(1) $[-\dfrac{1}{2},\dfrac{1}{2})\cup\{1\}$; (2) $[-\dfrac{\pi}{3},\dfrac{\pi}{3})$; (3) $\{-\dfrac{1}{2}\}$
040072
(1) $-\tan \alpha-\cot \alpha$; (2) $-\dfrac{\sqrt{2}}{\sin \alpha}$; (3) $-1$; (4) $0$
040073
040074
$-\dfrac{10}{9}$
040075
$a_n=\dfrac{1}{3n-2}$
040076
$a_n=\dfrac{1}{n}$
040077
$(n-\dfrac{4}{5})5^n$
040078
$2^{n+1}-3$
040079
$1078$
040080
$S_n=\begin{cases}\dfrac{n^2}{2}+n-\dfrac 23+\dfrac 23\cdot 2^n, & n\text{为偶数},\\ \dfrac{n^2}{2}-\dfrac 76+\dfrac 23\cdot 2^{n+1}, & n\text{为奇数} \end{cases}$
040081
(1) 略; (2) $n^2$
040082
(1) 不存在; (2) 存在, 如$c_n=2^{n-1}$
040083
$\dfrac{\sqrt{3}}{2}$
040084
$0$
040085
$\{0,-2\pi\}$
040086
$-\dfrac{\pi}6,\dfrac 56\pi$
040087
$\cot \alpha$
040088
$7+4\sqrt{3}$
040089
$\dfrac{\sqrt{2}-\sqrt{6}}{4}$
040090
$\dfrac{\sqrt{3}+\sqrt{35}}{12}$
040091
$\dfrac 12$
040092
$5$
040093
$-\dfrac 12$
040094
$\dfrac{\pi}{12}$
040095
$\{x|x=\pm\frac 23 \pi+2k\pi,k \in \mathbf{Z}\}$
040096
$\dfrac 43 \pi$
040097
\textcircled{4}
040098
C
040099
$\dfrac{-2\sqrt{2}-\sqrt{3}}6$
040100
$-\dfrac 7{25}$
040101
$-\dfrac {\pi}3$
040102
$(-\dfrac {12}{13}, \dfrac{5}{13})$
040103
$(\dfrac {5-12\sqrt{3}}{2}, \dfrac{12-5\sqrt{3}}{2})$
040104
040105
$\dfrac {171} {221}, -\dfrac {21} {221}$
040106
$\{-\pi\}$
040107
$\dfrac{8\sqrt{2}-3}{15}$
040108
$\sin \theta$
040109
$-\dfrac{56}{65}$
040110
$\dfrac {\pi}4$
040111
040112
040131
$-\dfrac{25}{12}$
040132
$\dfrac 52$
040133
$-\dfrac{\pi}4$
040134
$-\dfrac 12$
040135
$\dfrac 6{19}$
040136
$-\dfrac {\sqrt{3}}3$
040137
$\dfrac 3{22}$
040138
$4$
040139
$-\dfrac{63}{65}$
031288
$[7,10]$
031289
$(-\infty,-2)\cup(-2,3]$
031290
$2$
031291
$7$
031292
$a\ge3$
031293
$-9$或$3$
031294
$\dfrac{1}{27}$
031295
$[-3,3]$
031296
$45$
031297
$(1,\dfrac 32]$
031298
$[0,1]$
031299
$\dfrac{\sqrt{6}}{4}$
031300
D
031301
B
031302
A
031303
A
031304
$(1)a_n=-3n+19,b_n=4^{3-n}\\
(2)1\le n \le 28,S_n>T_n;n=29,S_n=T_n;n \ge 30,S_n<T_n $
031305
$(1)[-1,3];(2)a \ge 2$
031307
$(1)a_n=m^n;(2)m=\dfrac 13;(3)T_n=\dfrac {2n-3}4 \cdot 3^{n+1}+ \dfrac 94$
031308
$(1)(-\infty,2];(2)[2\sqrt{3},\dfrac{91}{20}];(3)a=-12,b=\dfrac{17}2$
040181
$\dfrac 7{25}$
040182
$-\dfrac{\pi}3+2k\pi,k \in \mathbf{Z}$
040183
$\dfrac{4\sqrt{3}-3}{10}$
040184
$\dfrac 17$
040185
$4\sqrt{2} \sin(\alpha+\dfrac {7}{4}\pi))$
040186
$3$
040187
$\dfrac 32$
040188
$\sqrt{3}$
040189
$2$
040190
$\dfrac {13}{18}$
040191
$\dfrac{7}{4}\pi$
040192
$\dfrac{64}{25}$
040193
C
040194
A
040195
B
040196
C
040197
$-\dfrac{\pi}6$
040198
$\dfrac 23 \pi$
040199
$\dfrac 32$
040200
$\sqrt{1-k}$
040201
$-\dfrac{484}{729}$
040226
$\dfrac 49 \sqrt{2}$
040227
$\sin \theta \cos \theta$
040228
$-\dfrac1{16}$
040229
$\dfrac 32$
040230
$\dfrac{13}{18}$
040231
$-2-\sqrt{7}$
040232
$\sin{\dfrac{\alpha}2}$
040233
$0$
040234
$\dfrac{120}{169}$
040235
$3$或$5$
040236
$\pi-\arcsin{\dfrac{24}{25}}$
040237
$\arcsin{\dfrac{3\sqrt{10}}{10}}$或$\arcsin{\dfrac{\sqrt{10}}{10}}$
040238
$60^{\circ}$或$120^{\circ}$
040239
$\dfrac 23 \pi$
040240
$8$
040241
\textcircled{4}
040242
$\dfrac 35$或$\dfrac{24}{25}$或$\dfrac{3\sqrt{10}}{10}$或$\dfrac{\sqrt{10}}{10}$
040243
(1)$\angle A=75^{\circ}, \angle B=45^{\circ}, a=\sqrt{2}+\sqrt{6}$\\
(2) $\angle B=60^{\circ}, \angle C=75^{\circ}, c=\sqrt{6}+3\sqrt{2}$或
$\angle B=120^{\circ}, \angle C=15^{\circ}, c=3\sqrt{2} - \sqrt{6}$
040244
$\dfrac 12$
040245
$\dfrac 12 \pm \dfrac{\sqrt{6}}5$
040246
$-\dfrac7{25}$
040247
$\dfrac {\sqrt{2}} 2 +\dfrac 14$
040248
$90^\circ$
040249
$\dfrac 1{a}$
040250
$-\dfrac{16}{65}$
040251
$\dfrac{24}{13}$
040252
$\dfrac{\sqrt{11}}{6}$
040253
直角三角形
040254
$120^\circ$
040255
$-\dfrac{48}{49}$
040256
等边三角形
040257
等腰三角形
040258
等腰或直角三角形
040259
$30^\circ$
040260
$30^\circ$或$90^\circ$或$150^\circ$
040261
$2\sqrt{7}$
040262
$\dfrac 12$
040263
$(0,\dfrac{\pi}4]$
040264
(1) $\dfrac 23 \pi$; (2) 等腰钝角三角形
040265
(1) $\dfrac{\sqrt{3}}6$; (2) $\dfrac{\sqrt{39}+\sqrt{3}}2$
040266
$\{x|\dfrac{\pi}6+2k\pi \le x \le \dfrac 56 \pi+2k\pi, k \in \mathbb{Z} \}$
040267
$[0,3)$
040268
$4$
040269
$\pi$
040270
$\pi$
040271
$\dfrac{\pi}{2}$
040272
$-\sin{\dfrac 12 -1}$
040273
\textcircled{2}\textcircled{3}\textcircled{5}
040274
等腰直角三角形
040275
$\{x|\dfrac{\pi}4+2k\pi \le x \le \dfrac 45 \pi+2k\pi, k \in \mathbb{Z} \}$
040276
$4\pi$
040277
$\dfrac{\pi}{2}$
040278
$\sqrt{5}$
040279
$12$
040280
$6+\sqrt{15}$
040281
\textcircled{3} \textcircled{4}
040282
(1) $b=1,c=\sqrt{13}$;\\
(2) 等腰三角形或直角三角形