添加一些备注
This commit is contained in:
parent
777cdb2da8
commit
f7e0d1c294
|
|
@ -1,98 +1,60 @@
|
|||
ans
|
||||
remark
|
||||
|
||||
018511
|
||||
$(\dfrac{x_1+\lambda x_2}{1+\lambda},\dfrac{y_1+\lambda y_2}{1+\lambda})$
|
||||
21786
|
||||
(20240430主要错因)忽略了``非零''这一条件
|
||||
|
||||
018516
|
||||
$(\dfrac{4}{5},\dfrac{3}{5})$处
|
||||
21803
|
||||
(20240507主要错因)仅有一解或计算错误
|
||||
|
||||
018517
|
||||
分别约为$101.5\text{N}$与$143.5\text{N}$
|
||||
24787
|
||||
(20240507主要错因)漏掉$x=0$这一可能
|
||||
|
||||
009638
|
||||
$9$
|
||||
21809
|
||||
(20240507其它)许多学生对于如何用向量语言表达``点在直线上''很不熟悉
|
||||
|
||||
009640
|
||||
$(0,15)$
|
||||
21812
|
||||
(20240507主要错因)部分学生仍忽略了平行的可能, 另一部分学生使用了$\cos\langle\overrightarrow{a},\overrightarrow{b}\rangle\in (-1,0)$来求解, 麻烦, 导致解错
|
||||
|
||||
009641
|
||||
(1) $\overrightarrow{f_2}=(1+\sqrt{3},3+\sqrt{3})$; (2) $30+10\sqrt{3}\text{J}$
|
||||
21813
|
||||
(20240507主要错因)不会用向量语言表示这个问题, 解错
|
||||
|
||||
009642
|
||||
$(\dfrac{8}{37},\dfrac{85}{37})$
|
||||
40727
|
||||
(20240507主要错误)$\dfrac{72}{25}$, $-\dfrac{72}{5}$
|
||||
|
||||
018519
|
||||
$-\dfrac{\overrightarrow{a}\cdot\overrightarrow{c}+\overrightarrow{b}\cdot\overrightarrow{d}}{\overrightarrow{a}^2+\overrightarrow{c}^2}$
|
||||
40721
|
||||
(20240507主要错误)$-3$或$2$, $1$
|
||||
(20240507主要错因)两边直接约分$k-1$; 观察到$k=1$时平行, 没有顾及必要性
|
||||
|
||||
018520
|
||||
$-\dfrac{5}{9}$
|
||||
|
||||
018526
|
||||
当且仅当$\theta=0$时, $\overrightarrow{BP}\cdot \overrightarrow{CQ}$的值最大, 最大值为$0$
|
||||
|
||||
018527
|
||||
(1) 是定值(定值为$1$), 理由略; (2) $3$
|
||||
24789
|
||||
(20240507主要错误)\textcircled{4}, \textcircled{2}\textcircled{3}\textcircled{4}, \textcircled{2}\textcircled{4}
|
||||
|
||||
|
||||
ans
|
||||
40714
|
||||
(20240507主要错误)对$\overrightarrow{AB}$和$\overrightarrow{BC}$的夹角错认为是$\angle ABC$
|
||||
(20240507其它)大部分学生使用了余弦定理求角, 会用向量语言求这个数量积的很少
|
||||
|
||||
040738
|
||||
$-3$
|
||||
40735
|
||||
(20240507主要错因)(2) 部分学生仍忽略了平行的可能, 另一部分学生使用了$\cos\langle\overrightarrow{a},\overrightarrow{a}+k\overrightarrow{b}\rangle\in (0,1)$来求解, 麻烦, 导致解错
|
||||
|
||||
040739
|
||||
$\dfrac{\pi}{2}$
|
||||
24791
|
||||
(20240507主要错因)不会用分解的方式来求解
|
||||
|
||||
024816
|
||||
$\dfrac{1}{2}\overrightarrow{e_1}$
|
||||
17646
|
||||
(20240507主要错误)$\dfrac{23}{18}$和其它一些零散的答案, 部分带有$\sqrt{2}$(如$\dfrac{17+6\sqrt{2}}{18}$)
|
||||
|
||||
040741
|
||||
$(-5,-5)$
|
||||
|
||||
040742
|
||||
$[0,2]$
|
||||
24793
|
||||
(20240507主要错因)做不到二次函数的结构; 做到二次函数的结构后未关注``在线段上''带来的定义域导致求得的是全局最小值$-\dfrac{9}{4}$
|
||||
(20240507主要错误)$-\dfrac{9}{4}$
|
||||
|
||||
040743
|
||||
$(-\dfrac{7}{9},-\dfrac{7}{3})$
|
||||
|
||||
040744
|
||||
$11$或$-2$
|
||||
40715
|
||||
(20240507主要错因)(1)用相位在$[2k\pi-\dfrac{\pi}{2},2k\pi+\dfrac{\pi}{2}]$来求严格减区间
|
||||
(20240507主要错因)(2)未想到用角的正弦来表示$b+2c$; 对角的范围不敏感; 对于含非特殊角的三角函数不会求值域
|
||||
|
||||
040747
|
||||
$(-\infty,-4)\cup (-4,1)$
|
||||
10002
|
||||
(20240507主要错因)(2)对角的范围不敏感; 对于含非特殊角的三角函数不会求值域
|
||||
|
||||
040746
|
||||
$\sqrt{3}$
|
||||
|
||||
040749
|
||||
$[\dfrac{1}{2},1]$
|
||||
|
||||
024815
|
||||
$1-\sqrt{2}$
|
||||
|
||||
040751
|
||||
$\arccos\dfrac{1}{7}$
|
||||
|
||||
024788
|
||||
$\dfrac{3}{11}$
|
||||
|
||||
024789
|
||||
\textcircled{3}\textcircled{4}
|
||||
|
||||
024790
|
||||
D
|
||||
|
||||
024791
|
||||
$\overrightarrow{a}=-\sqrt{3}\overrightarrow{b}-\dfrac{1}{3}\overrightarrow{c}$
|
||||
|
||||
017646
|
||||
$\dfrac{19}{18}$
|
||||
|
||||
024792
|
||||
$\dfrac{3}{8}\overrightarrow{a}+\dfrac{1}{4}\overrightarrow{b}$
|
||||
|
||||
024793
|
||||
$-\dfrac{11}{16}$
|
||||
|
||||
010002
|
||||
(1) $\arccos\dfrac{13}{14}$; (2) $28\sqrt{74}$
|
||||
|
||||
|
|
|
|||
Reference in New Issue