20-21高二·全国·课后作业
名校
1 . 如图,四棱锥
的底面是边长为2的正方形,
平面ABCD,且
,
是PB 上一个动点,过点
作平面
平面PAD,截棱锥所得图形面积为y,若平面
与平面PAD之间的距离为x,则函数
的图像是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bab2c27eac56fffa4cd7dbe1dcdf1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f31e45e4cb398f3c74aed277d6b72515.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2 . 如图①,在等腰
中,点
是底边
的中点,将
沿
折至
的位置.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/3/fbb6fb18-33ee-48dd-ac7f-7d0deff57135.png?resizew=174)
(1)求证:
平面
.
(2)若三棱锥
的三视图为图②所示的三个直角三角形,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e195f36d43128197ea62c7f53ed57197.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fded87a08e621a0aa62659e26232f85c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/3/fbb6fb18-33ee-48dd-ac7f-7d0deff57135.png?resizew=174)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ce03b310edce42191f9fa75a1c909ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/739c629772c553e9a2329d5d71173736.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32c9a742c1e218d1fcdb92bce78123e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d3bceb0faeccb4766590b1da63f38a6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/3/b3175e44-7823-4a0c-adc1-8d2d163e5261.png?resizew=289)
您最近一年使用:0次