![](https://staticzujuan.xkw.com/quesimg/Upload/formula/565bc68d208cd5e0c90a32851faf3814.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9b06b190b43f7dd6de243d445acf82b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/309f537e5bd6c092d0017bb1e4d3cc83.png)
(1)求B;
(2)若点D在AC上,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/417a1d5c9063a6eb4a3e6391ee44e771.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11f787941cb1abfe9bb757276b765c0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcc4fc72e73c581887f1a5a09ad97efc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b294af6c6bb9f1f8640927cc55b05b90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77c352e5cbef8b1f99c997f8b246a90f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/30/f2829b3e-2eab-4208-9094-00a6fcb4d99f.png?resizew=158)
A.![]() | B.![]() |
C.![]() | D.![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59c709117ab1d3ef620883a732aed68b.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b9cb8e6ff801523b0304576cd69fd2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/797e67927616b141ed7c6b83f8b6f4fb.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59c709117ab1d3ef620883a732aed68b.png)
5 . 已知直线l:经过抛物线C:
(
)的焦点F,与抛物线交于A,B两点.过A,B两点且与抛物线相切的直线相交于点P.
(1)求抛物线的标准方程;
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0893a169bb1e790ce73c62f63c59ab48.png)
6 . 如图,在四棱锥中,底面ABCD为矩形,侧面PAB为等边三角形,且侧面
底面ABCD,
,E,F分别为PA,BC的中点,G为AE的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/1/87e90dd9-50f6-4933-9153-4501c13f6c69.png?resizew=168)
(1)证明:BG∥平面EFD;
(2)求平面DEF与平面DCP夹角的余弦值.
7 . 与大家熟悉的黄金分割相类似的还有一个白银分割,比如A4纸中就包含着白银分割率.若一个数列从0和1开始,以后每一个数都是前面的数的两倍加上再前面的数:0,1,2,5,12,29,70,169,408,985,2378,…,则随着n趋于无穷大,其前一项与后一项的比值越来越接近白银分割率.记该数列为,其前n项和为
,则下列结论正确的是( )
A.![]() ![]() | B.![]() |
C.![]() | D.![]() |
8 . 已知有两个极值点
.
(1)求实数a的取值范围;
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3808f231a23dd0789780f9bbbf93c989.png)
9 . 已知函数,下列结论中正确的有( )
A.函数![]() ![]() |
B.若![]() ![]() |
C.函数![]() ![]() |
D.函数![]() ![]() ![]() |
10 . 如图是一个空气开关,又名空气断路器,是家中非常重要的一种电器,它集控制和多种保护功能于一身,能对电路或电气设备发生的短路、严重过载及欠电压等进行保护.某学校配电房共有18个空气开关排成一列,电工准备进行电路调试,打算关闭3个,头尾不能关闭,关闭的相邻两个开关之间至少有两个是打开的,则不同的方案种数是( )
A.220 | B.364 | C.560 | D.680 |