名校
解题方法
1 . 如图所示,
是圆锥的一部分(A为圆锥的顶点),
是底面圆的圆心,
,
是弧
上一动点(不与
、
重合),满足
.
是
的中点,
.
![](https://img.xkw.com/dksih/QBM/2022/2/10/2913473877712896/2921446104268800/STEM/dd013b3a-2267-4654-8cdc-88b6edd2d93f.png?resizew=136)
(1)若
平面
,求
的值;
(2)若四棱锥
的体积大于
,求三棱锥
体积的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad7d022859b8853d7be8f2bf6487a693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8026ad627e8ae6c4acb9140a02181f29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21b710be34d39a3058bad08e397849e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5811e450dcff0e190c3d7378c08797c5.png)
![](https://img.xkw.com/dksih/QBM/2022/2/10/2913473877712896/2921446104268800/STEM/dd013b3a-2267-4654-8cdc-88b6edd2d93f.png?resizew=136)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3123da0313d458c833e82aaa234b9117.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ed01d1ff5a7f21a68fb3a1e5c7f393e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de7d5ef3a3d9a03be91135fc426d57cc.png)
(2)若四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f28ba8a560e3b54f9346f2a6a805c016.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d266a04f3dc7483eddbc26c5e487db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40cc229e0951e5d141f3c8341d17c593.png)
您最近一年使用:0次
2022-02-21更新
|
1656次组卷
|
6卷引用:浙江省2022届高三毕业生“极光杯”线上综合测试IV数学试题
浙江省2022届高三毕业生“极光杯”线上综合测试IV数学试题(已下线)重难点03 立体几何与空间向量-2022年高考数学【热点·重点·难点】专练(全国通用)浙江省舟山市普陀中学2022届高三下学期3月月考数学试题湖南省长沙市雅礼中学2024届高三上学期月考(二)数学试题(已下线)湖南省长沙市雅礼中学2024届高三上学期月考(二)数学试题变式题19-22上海市闵行区七宝中学2024届高三下学期3月月考数学试题
解题方法
2 . 如图,在长方体
中,E,F分别是
,
的中点.
![](https://img.xkw.com/dksih/QBM/2022/1/18/2897166202675200/2921334978387968/STEM/ae098f6be916476b92d9a3158f2d97c3.png?resizew=271)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
平面
;
(2)若
,求平面AEF与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://img.xkw.com/dksih/QBM/2022/1/18/2897166202675200/2921334978387968/STEM/ae098f6be916476b92d9a3158f2d97c3.png?resizew=271)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82b724168afaee2ecddf97257180be18.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/876a5f5b6c620b8f6af8c011d1868791.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/544133e145fa7cc6782e675a0892bd4f.png)
您最近一年使用:0次
解题方法
3 . 在直四棱柱
中,底面
是正方形,
,
,点E,M,N分别是
,
,
的中点.
![](https://img.xkw.com/dksih/QBM/2022/1/25/2902237644988416/2916951566811136/STEM/112e4b38-5dca-4fdc-9150-c9e6f740e01f.png?resizew=149)
(1)求证:
平面
;
(2)求点N到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55a2310cbba5e050488cd9296eb195d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f66fb71b75b63594ebeeeebd1963eed5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/2022/1/25/2902237644988416/2916951566811136/STEM/112e4b38-5dca-4fdc-9150-c9e6f740e01f.png?resizew=149)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87fd07724203a844a89c846399fc65e0.png)
(2)求点N到平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87fd07724203a844a89c846399fc65e0.png)
您最近一年使用:0次
名校
4 . 在如图所示的圆柱
中,
为圆
的直径,
、
是
的两个三等分点,
、
、
都是圆柱
的母线.
![](https://img.xkw.com/dksih/QBM/2022/4/24/2965187534807040/2998300579651584/STEM/53fbef0c3f8a49049af2c1e36848a21c.png?resizew=175)
(1)求证:
平面
;
(2)若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e65ac334119ccd6204402a7aba29a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1642eec556eb252de9c1ab7bb5ca90b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/735056c174e8dd7906257a2a50a962a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4083c581c6027c4b2ae7e3b3749f485.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e65ac334119ccd6204402a7aba29a55.png)
![](https://img.xkw.com/dksih/QBM/2022/4/24/2965187534807040/2998300579651584/STEM/53fbef0c3f8a49049af2c1e36848a21c.png?resizew=175)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15d8662513d307ed16683319e997494d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/797835e3ba47ab72406d50249adeb593.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a38a3e226347af68d7b15295342e209.png)
您最近一年使用:0次
2022-06-10更新
|
1274次组卷
|
12卷引用:湖南省永州市2021届高三下学期二模数学试题
湖南省永州市2021届高三下学期二模数学试题四川省成都市石室中学2021届高三三模模拟考试数学试题(已下线)专题37 仿真模拟卷03-2021年高考数学(理)二轮复习热点题型精选精练(已下线)精做04 立体几何-备战2021年高考数学大题精做(新高考专用)(已下线)专题1.7 空间向量与立体几何-2021年高考数学解答题挑战满分专项训练(新高考地区专用)江苏省徐州市2021届高三下学期第三次调研测试数学试题西藏自治区拉萨中学2021届高三第八次月考数学(理)试题山东师范大学附属中学2021-2022学年高三下学期4月线上测试数学试题(已下线)2022年全国新高考II卷数学试题变式题13-16题(已下线)2022年全国新高考II卷数学试题变式题20-22题(已下线)1.2.4 二面角新疆巴音郭楞蒙古自治州若羌县中学2022-2023学年高二下学期3月月考数学试题
5 . 如图所示的四棱锥
的底面
是一个等腰梯形,
,且
,
是
的中线,点
是棱
的中点.
![](https://img.xkw.com/dksih/QBM/2021/12/29/2883068883615744/2886408744034304/STEM/bcde2e88-cdec-4b1c-b8ab-f5c677187bd7.png?resizew=156)
(1)证明:
平面
.
(2)若平面
平面
,且
,
,求平面
与平面
所成锐二面角的余弦值.
![](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/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e62ca104bd39a1646922b5836f1826b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef49a3ca580a144cc65a609c167facc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/2021/12/29/2883068883615744/2886408744034304/STEM/bcde2e88-cdec-4b1c-b8ab-f5c677187bd7.png?resizew=156)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d27ff0b39832f094ec51e28721d739.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62974d34de3a12418d6b700420afd1b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb201fb1a8247cee1cd3aa2bf33690f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
您最近一年使用:0次
2022-01-03更新
|
986次组卷
|
5卷引用:河南省2021-2022学年高三上学期第五次联考理科数学试题
河南省2021-2022学年高三上学期第五次联考理科数学试题广东省部分学校2022届高三上学期12月联考数学试题(已下线)专题3.1 模拟卷(1)-2022年高考数学大数据精选模拟卷(新高考地区专用)(已下线)专题10 盘点求二面角的三种方法-2(已下线)专题3.3 选修一+选修二第四章数列(中)-【满分计划】2021-2022学年高二数学阶段性复习测试卷(人教A版2019选择性必修第二册)
名校
6 . 在四棱锥
中,
为等边三角形,
,
,点
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/4c468772-4545-427d-80f7-0acc2356e067.png?resizew=198)
(1)求证:
平面
;
(2)已知平面
平面
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661ff55b5ebbadfb600989af3cfce2fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32450995497b9e341be832e9efad3114.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4ad161a2674d823247f0d8236cae1d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/4c468772-4545-427d-80f7-0acc2356e067.png?resizew=198)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7175df06e33cad4e6bbc3f2f6b0a2986.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)已知平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f04c222223dae9ef27d4c132534d9848.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d5a2f5f4970ab8a1303523e23c8b24a.png)
您最近一年使用:0次
2021-10-09更新
|
1522次组卷
|
5卷引用:四川省成都市锦江区嘉祥外国语高级中学2023届高三下学期三诊模拟考试(理科)数学试题
名校
解题方法
7 . 如图所示的几何体中,
是菱形,
,
平面
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/fb3f00da-50a3-418b-9668-4af24be97dab.png?resizew=189)
(1)求证:
平面
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.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/ab2addb6ef9ede5e234f4b363f5dc0e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57dfec4b826f33d0fd5e9664f52ae2fa.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/fb3f00da-50a3-418b-9668-4af24be97dab.png?resizew=189)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30067b7b236d17af8a462f96a58d11bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b115316e0fcd2ef46a4dd383472996e4.png)
您最近一年使用:0次
2021-09-30更新
|
313次组卷
|
4卷引用:陕西省榆林市米脂中学2021-2022学年高三上学期四模理科数学试题
名校
8 . 如图,在直四棱柱
中,底面四边形
为梯形,点
为
上一点,且
,
,
.
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712443946426368/2751503424200704/STEM/69e30653-fa4b-4267-9015-e590f7fbfe3e.png?resizew=175)
(1)求证:
平面
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b86cde4e24036082b9c92253a6f579e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3dd2f888f1b9d7f522e6248ce957a688.png)
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712443946426368/2751503424200704/STEM/69e30653-fa4b-4267-9015-e590f7fbfe3e.png?resizew=175)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21c8f2410d6a17adcf6817b08d20f3ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ded2e3fdcab984f3699972fc3ff75d5.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49f0f42dd7ab21d2057ef8b7a1a640fd.png)
您最近一年使用:0次
2021-06-26更新
|
345次组卷
|
3卷引用:四川省遂宁市2021届高三三三模数学(理)试题
四川省遂宁市2021届高三三三模数学(理)试题(已下线)考点33 直线、平面平行的判定及其性质-备战2022年高考数学(理)一轮复习考点帮四川省内江市第六中学2021-2022学年高三上学期第一次月考数学(理科)试题
名校
解题方法
9 . 如图,在直四棱柱
中,底面四边形
为梯形,点
为
上一点,且
,
,
.
![](https://img.xkw.com/dksih/QBM/2021/6/5/2736394871193600/2737819917500416/STEM/81210a37863449af8959795daea8687a.png?resizew=144)
(1)求证:
平面
;
(2)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b86cde4e24036082b9c92253a6f579e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5d3aaafa4e988aee932be29cf5ac0e.png)
![](https://img.xkw.com/dksih/QBM/2021/6/5/2736394871193600/2737819917500416/STEM/81210a37863449af8959795daea8687a.png?resizew=144)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21c8f2410d6a17adcf6817b08d20f3ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ded2e3fdcab984f3699972fc3ff75d5.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4294ffdba16ae69fd03b13959d682aba.png)
您最近一年使用:0次
2021-06-07更新
|
822次组卷
|
6卷引用:安徽省蚌埠市第二中学2021届高三下学期高考最后一模文科数学试题
安徽省蚌埠市第二中学2021届高三下学期高考最后一模文科数学试题四川省遂宁市2021届高三三模数学(文)试题(已下线)考点32 直线、平面平行的判定及其性质-备战2022年高考数学(文)一轮复习考点帮山西大学附属中学2022届高三上学期11月期中数学(文)试题山西省吕梁学院附属高级中学2022届高三上学期期中数学(文)试题河南省名校联盟2021-2022学年上学期高三第一次诊断考试文科数学试题
解题方法
10 . 已知多面体
如图所示,其中四边形
为矩形,
,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/42a16c44-24cf-4129-81f3-46732e7a0052.png?resizew=151)
(1)求证:
平面
;
(2)若
,点
到平面
的距离为
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7a4b0915461cea741269f7f2c186b0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/42a16c44-24cf-4129-81f3-46732e7a0052.png?resizew=151)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b78172568aac9805d2ea2d5f742bf80c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3214c853ea2268ef6c434fb28f0298d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae8768996ca9a0f2c5d9a19abbd54df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fdabfda983e4003ba180a69fde0c727b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5509269c540ac83ba34d2e8a31242903.png)
您最近一年使用:0次