1 . 如图,在等腰梯形
中,
,
,
,四边形
为矩形,
,平面
平面
,点
为线段
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/630533f7-5a96-4430-ba51-e7793afb6972.png?resizew=193)
(1)求异面直线
与
所成的角的正切值;
(2)求证:平面
平面
;
(3)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08062a925efb07c38a229b8628e3b41f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bbc56d42b003cbcb1fbe5c50e55b26b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ea37f262f50b2c43b5c5fba506f3f39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c0db1f4f666a9be9ede868065a50997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/630533f7-5a96-4430-ba51-e7793afb6972.png?resizew=193)
(1)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c884b508394b3ab50734b584d9ec783c.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e168d7f1f1a0d260af3c8ca404c2f09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2730b513bd3359c3dfe6567e04f5ef9.png)
(3)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176385d91d5e29324fce4a932eff6a79.png)
您最近一年使用:0次
2 . 如图:在四棱锥
中,底面
是菱形,
底面
,
是
中点,
是
中点.
(1)求证:
平面
;
(2)求直线
与平面
所成角的正切值;
(3)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f8ea41444c650bc66b9a0052a7c3e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c372d059202ec388960b125d4a87dc84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fbbe7f48676298f2ee0cb1901992eaf.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/013e58ab92ebfc889e2e0e2be903792e.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16fd1bc6147d69777b26a35d48522f7e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/28/8c5b0d9c-7e0f-478b-8750-f43532db2bbb.png?resizew=161)
您最近一年使用:0次
名校
解题方法
3 . 如图在四棱锥
中,
平面
,
,且
平分
与
交于
点,
为
的中点,
.
![](https://img.xkw.com/dksih/QBM/2017/6/18/1711736818982912/1712243329925120/STEM/29f27b51483442cc9f7b96ffe06e9703.png?resizew=193)
(1)证明
平面
;
(2)证明
平面
;
(3)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d97dc3b752832906de41447bb58a341.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0ebcc5c0a70cc1a34eb70d0b578d688.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3da2419b0f9374f8bffe4ab679ef0e05.png)
![](https://img.xkw.com/dksih/QBM/2017/6/18/1711736818982912/1712243329925120/STEM/29f27b51483442cc9f7b96ffe06e9703.png?resizew=193)
(1)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/373f735f0f04d11f1951eaef1bb78b6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(2)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4a79fe6289d42058b781171fbd0b92e.png)
您最近一年使用:0次
4 . 如图,在四棱锥
中,
平面
,
,且
,
,
为线段
上一点,
,且
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/e4c0bcf1-471d-46aa-9e4c-2f062dcb24fe.png?resizew=208)
(1)证明:
平面
;
(2)求证:平面
平面
;
(3)求直线
与平面
所成角的正弦值.
![](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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dd8c48af35b84b863cea79e2bd81c87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f14fe22376f70a50752d3e146b8e1b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eeef1db30212433062b3297569a7aafd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/e4c0bcf1-471d-46aa-9e4c-2f062dcb24fe.png?resizew=208)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89571b0ed015bc7533d44b73a74ba309.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(3)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c5757f787d98f9a46777324b69ad672.png)
您最近一年使用:0次
解题方法
5 . 如图,在四棱锥
中,
底面
,底面
是直角梯形,
,
,
是
上的一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/317ae1a1-a491-4317-84ab-065a82998917.png?resizew=240)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/018ec5bd-d0f2-4f57-b41a-5027fe0167b4.png?resizew=244)
(1)求证:平面
平面
;
(2)如图(1),若
,求证:
平面
;
(3)如图(2),若
是
的中点,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0465d52848d924b0576172c9b22a831.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fd3c2e2199cd4565c05b949bc21fc37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87827211113fd8f5d1afd793927222d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/317ae1a1-a491-4317-84ab-065a82998917.png?resizew=240)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/018ec5bd-d0f2-4f57-b41a-5027fe0167b4.png?resizew=244)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/677d1863ff4d8ac1604b18149d4f320f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)如图(1),若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ceca6155563238c77dee3fdc735637b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36222db36e348661eb5f616820e4e60f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca48c18021e7be4bbb3e95576e1c1b5f.png)
(3)如图(2),若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2899e607479d8d1c47d954ae9ebb7144.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5102c216393e133fa25dba98cd78535.png)
您最近一年使用:0次
6 . 已知圆C的圆心在直线l:y=2x上,且经过点A(﹣3,﹣1),B(4,6).
(Ⅰ)求圆C的方程;
(Ⅱ)点P是直线l上横坐标为﹣4的点,过点P作圆C的切线,求切线方程.
(Ⅰ)求圆C的方程;
(Ⅱ)点P是直线l上横坐标为﹣4的点,过点P作圆C的切线,求切线方程.
您最近一年使用:0次
7 . 如图,在四棱锥
中,底面
是矩形.已知
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2017/12/5/1831766170238976/1834044634365952/STEM/221fd5e52ad74d908101366e46701c4a.png?resizew=195)
(Ⅰ) 证明:
平面
;
(Ⅱ)求异面直线
与
所成角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b755b7f230066d649c18e30dd640f6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b80ee363635d73f601654339028daec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed6281306726065e7075c579b9b66537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64e68018750dcdcb6a346761c96a45cf.png)
![](https://img.xkw.com/dksih/QBM/2017/12/5/1831766170238976/1834044634365952/STEM/221fd5e52ad74d908101366e46701c4a.png?resizew=195)
(Ⅰ) 证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(Ⅱ)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
您最近一年使用:0次
2017-12-08更新
|
474次组卷
|
2卷引用:天津市耀华中学2018届高三上学期第一次月考数学(文)试题2
8 . 如图,在三棱柱
中,侧棱
底面
,
,
为
的中点,
,四棱锥
的体积为
.
![](https://img.xkw.com/dksih/QBM/2017/12/12/1836779429003264/1836944838909952/STEM/b1c7e5c38d11459cb7522eca435c00d7.png?resizew=203)
(Ⅰ)求证:
平面
;
(Ⅱ)求直线
与平面
所成角的正弦值;
(Ⅲ)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4339a40ae9d1947ec3a4b3e2fa3a16cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb420e9a5faa91baf74a2f687b30f514.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://img.xkw.com/dksih/QBM/2017/12/12/1836779429003264/1836944838909952/STEM/b1c7e5c38d11459cb7522eca435c00d7.png?resizew=203)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be0c0d0497f5d3f317504d59cc19a4c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a935b7d21a103a264b6e96ecf82dbe4a.png)
(Ⅱ)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bf9628142422a4884bd59538da6d312.png)
(Ⅲ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50d60aaf524b4c2eec5229f9f204ce51.png)
您最近一年使用:0次
9 . 如图,
是平行四边形,
平面
,
//
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2017/10/13/1794282516774912/1794471202021376/STEM/9f2bf70c6a4e4510a99b1859f87f1aab.png?resizew=252)
(1)证明:
//平面
;
(2)求证:平面
平面
;
(3)求直线
与平面
所成角的正弦值;
(4)求二面角
的平面角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f95475bfc06e884754eb4a455c3f434e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9b5d2943803894bc5d204e75e2d172b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f04edd173055da613832b187737ce4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d31430a87a688a727b86e4001dcb3e6.png)
![](https://img.xkw.com/dksih/QBM/2017/10/13/1794282516774912/1794471202021376/STEM/9f2bf70c6a4e4510a99b1859f87f1aab.png?resizew=252)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8257b6bd25104e07b9ad935c0a3aac4.png)
(3)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fdd5861601a5e5aaa35dc70b902fd381.png)
(4)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69076a8440ebd8d01106579c7b5bce62.png)
您最近一年使用:0次
10 . 已知
为坐标原点,设动点
.
(1)当
时,若过点
的直线
与圆
:
相切,求直线
的方程;
(2)当
时,求以
为直径且被直线
截得的弦长为2的圆的方程;
(3)当
时,设
,过点
作
的垂线,与以
为直径的圆交于点
,垂足为
,试问:线段
的长是否为定值?若为定值,求出这个定值;若不为定值,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b66d7c33f780e88974ca92bd3c260eb8.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a74f3b5fdb1e8e26ebf614b10a975afd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7975636f6315bacd0246474a3a389ddb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce7cc6eaac685821b9e9bf48c60438c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3369e0ea90e8d5cf4b6b3c45c0fd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da5e4f21b648c27d55b12c8d42ada6f9.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce7cc6eaac685821b9e9bf48c60438c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c6ff81aedbefa935da289dc632e78eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3369e0ea90e8d5cf4b6b3c45c0fd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3369e0ea90e8d5cf4b6b3c45c0fd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88e9f7d1272b7344346b58b660aa260a.png)
您最近一年使用:0次