如图,已知
为
的直径,点D为
上一点,
于点C,交
于点E,
与
的延长线交于点F,
平分
.
![](https://img.xkw.com/dksih/QBM/2022/5/25/2986951193460736/2992533515649024/STEM/4dd5dbe6-cb97-4730-9be4-e81499305a9b.png?resizew=220)
(1)求证:
是
的切线;
(2)若
,
,直接写出
的长________.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bd6a2b112facda441f4e34bf5c145fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://img.xkw.com/dksih/QBM/2022/5/25/2986951193460736/2992533515649024/STEM/4dd5dbe6-cb97-4730-9be4-e81499305a9b.png?resizew=220)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc34db5860990e51ba31edc8cdd077c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/348fb71fbc47fd87e9ce011652ef4186.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
更新时间:2022-06-02 09:47:56
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】用两种方法证明“直角三角形斜边上的中线等于斜边的一半”.
中,
,O为
的中点.
求证
.
证法1:延长
到点D,使
,连接
.
∵O为
的中点,
∴
_________(依据是_________).
∵
,
∴
垂直平分
.
∴
_________.
∴
.
请把证法1补充完整,并用不同的方法完成证法2.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7582af1fc3000103c72cbca34441542a.png)
证法1:延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f213621229843639780aae87fa29584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
∵O为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40b54832529491611246a62c8475af52.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fe0cbc27f7482d769109b2b0def87cc.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d97dc3b752832906de41447bb58a341.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c26a46e7879436d532af3f4b6e258a81.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7582af1fc3000103c72cbca34441542a.png)
请把证法1补充完整,并用不同的方法完成证法2.
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【推荐2】如图,在坡角为28°的山坡上有一铁塔AB,其正前方矗立着一大型广告牌,当阳光与水平线成45°角时,测得铁塔AB落在斜坡上的影子BD的长为10米,落在广告牌上的影子CD的长为6米,求铁塔AB的高.(AB、CD均与水平面垂直,结果保留一位小数,参考数据:sin28°≈0.47,cos28°≈0.88)
![](https://img.xkw.com/dksih/QBM/2020/10/14/2571051402895360/2573192362614784/STEM/773c4b3d5fcd47a7bd247be0aac01678.png?resizew=165)
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【推荐3】图,平面直角坐标系中,
是坐标原点,直线
经过点
,与
轴交于点
,与
轴交于点
.线段
平行于
轴,交直线
于点
,连接
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/9/e51fbc72-8029-450f-8dd4-1ec5940aa897.png?resizew=140)
(1)填空:
______,点
的坐标是(______,______);
(2)求证:四边形
是平行四边形;
(3)动点
从点
出发,沿对角线
以每秒1个单位长度的速度向点
运动,直到点
为止;动点
同时从点
出发,沿对角线
以每秒1个单位长度的速度向点
运动,直到点
为止.设两个点的运动时间均为
秒.
①当
时,
的面积是______.
②在点
,
运动过程中,当
时请直接写出此时
的值______.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ce9a273c93c58d270bca6f162779c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dcfb4f2163f18747b4f92917918d60c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f86bebdf5931efbdc627baa52f97392e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/9/e51fbc72-8029-450f-8dd4-1ec5940aa897.png?resizew=140)
(1)填空:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd707b69a11f8de5566f23c1a2a9ff5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
(2)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d439e428bc3bf8778c274dd683f4fde9.png)
(3)动点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71b63d2504bd3ecce8c10560b142356f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
①当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cbeede118c407a800b05757b9a1393e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e87b2f781cafa7989d81f9bf8c42b150.png)
②在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd3d2a3196989c609816bfcb3c406ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
您最近一年使用:0次
解答题-证明题
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(0.65)
【推荐1】如图,
内接于
,
的延长线交
于点
,交
于点
,过点
作
交
于点
,连接
,
.
(1)若
,求证:
;
(2)求证:点
到
的距离等于
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fda6d76fb350332472e76fefcca6a9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/23/9d5d4a10-4abf-4b30-b828-3ef5290fb373.png?resizew=172)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac52d97c07b4c2d57f09edccdecce6a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0105d0889f6fa9cb5430cf9e09337173.png)
(2)求证:点
![](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/378fb04b88d74f59fb04ed5a56de5eb7.png)
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(0.65)
【推荐2】如图,在
中,弦
相交于点E,连接
,已知
.
;
(2)如果
的半径为5,
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa16498b83d2df4608888d3f4466e2cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b82b8d1176541eb689d9d04da4b9329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba11242dcc61d3c7c3555b598b5fdc89.png)
(2)如果
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72e7358c70d6b8c472030b0f3aca786c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
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(0.65)
【推荐1】已知线段
是⊙
的直径,
,点A为
上一点,
平分
交
于点D.
,求证:
是
的切线;
(2)如图2,连接
,
,若
,
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abcb980da8e86b4cfd322616dc84fc6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c436f108fd4921dae15ecff19270237e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(2)如图2,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d8d012fae1e0ad41d283ce648f05007.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54275b7e571660d0a9e0370fbfe5050b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/101bb72104105c615f95d7aede1a9c29.png)
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【推荐2】如图,
是
的直径,点A是
上异于C,D的一点,点B是
延长线上一点,连接
,
,
,且
.
(1)求证:直线
是
的切线;
(2)若
,作
的平分线
交
于点P,交
于点E,连接
、
,若
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0eacda8e4cd7f3712cb8f514cc13b5c9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/16/993126f5-e530-4ecc-9e36-73474ba767a3.png?resizew=239)
(1)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38586fe93acaacaeabe67feea485b92b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5157b42da58d55daad27d98b2fec15ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04be58ea6ca37a850422631eb3e994d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16f7be9d7393f24e4bb12298dd016c6d.png)
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真题
【推荐1】【探索发现】
如图①,是一张直角三角形纸片,∠B=90°,小明想从中剪出一个以∠B为内角且面积最大的矩形,经过多次操作发现,当沿着中位线DE、EF剪下时,所得的矩形的面积最大,随后,他通过证明验证了其正确性,并得出:矩形的最大面积与原三角形面积的比值为 .
【拓展应用】
如图②,在△ABC中,BC=a,BC边上的高AD=h,矩形PQMN的顶点P、N分别在边AB、AC上,顶点Q、M在边BC上,则矩形PQMN面积的最大值为 .(用含a,h的代数式表示)
【灵活应用】
如图③,有一块“缺角矩形”ABCDE,AB=32,BC=40,AE=20,CD=16,小明从中剪出了一个面积最大的矩形(∠B为所剪出矩形的内角),求该矩形的面积.
【实际应用】
如图④,现有一块四边形的木板余料ABCD,经测量AB=50cm,BC=108cm,CD=60cm,且tanB=tanC=
,木匠徐师傅从这块余料中裁出了顶点M、N在边BC上且面积最大的矩形PQMN,求该矩形的面积.
如图①,是一张直角三角形纸片,∠B=90°,小明想从中剪出一个以∠B为内角且面积最大的矩形,经过多次操作发现,当沿着中位线DE、EF剪下时,所得的矩形的面积最大,随后,他通过证明验证了其正确性,并得出:矩形的最大面积与原三角形面积的比值为 .
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/12/ad440000-a1ad-4333-ae7a-d90fb642d88e.png?resizew=528)
【拓展应用】
如图②,在△ABC中,BC=a,BC边上的高AD=h,矩形PQMN的顶点P、N分别在边AB、AC上,顶点Q、M在边BC上,则矩形PQMN面积的最大值为 .(用含a,h的代数式表示)
【灵活应用】
如图③,有一块“缺角矩形”ABCDE,AB=32,BC=40,AE=20,CD=16,小明从中剪出了一个面积最大的矩形(∠B为所剪出矩形的内角),求该矩形的面积.
【实际应用】
如图④,现有一块四边形的木板余料ABCD,经测量AB=50cm,BC=108cm,CD=60cm,且tanB=tanC=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d599cb4a589f90b0205f24c2e1fa021e.png)
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解答题-证明题
|
适中
(0.65)
【推荐2】如图,在正方形
中,E是
上一点,连接
.过点A作
,垂足为F,
经过点C、D、F,与
相交于点G.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/16/84754cae-bc09-4f8e-9868-c94cf5a90dbb.png?resizew=166)
(1)求证:
;
(2)若正方形
的边长为1,
,求
的半径.
(3)若
,
,求y关于x的函数关系式.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/876bb8ce0ca53475fa091ffd18bdc94a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/16/84754cae-bc09-4f8e-9868-c94cf5a90dbb.png?resizew=166)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae42d0475adf6f9f179d54f680a93a8.png)
(2)若正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9706d34a505d6071280c08c0cdd9759.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6f007df579861764f8cffc170e31bfc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68f64a23d85a1705e8a8e48d168c7541.png)
您最近一年使用:0次