如图,在Rt△ABC中,∠C=90°,AB=10cm,AC=6cm,动点P从点B出发,沿射线BC以4cm/s的速度运动,设运动时间为t秒.
(1)当t= 时,AP平分△ABC的面积.
(2)当△ABP为等腰三角形时,求t的值.
(3)若点Q是边AB上一点,且QP⊥BC,垂足为P,请用无刻度的直尺和圆规,作出点P、点Q,使得QA=QP.
(4)若点E、F为BC、AB上的动点,求AE+EF的最小值.
(1)当t= 时,AP平分△ABC的面积.
(2)当△ABP为等腰三角形时,求t的值.
(3)若点Q是边AB上一点,且QP⊥BC,垂足为P,请用无刻度的直尺和圆规,作出点P、点Q,使得QA=QP.
(4)若点E、F为BC、AB上的动点,求AE+EF的最小值.
![](https://img.xkw.com/dksih/QBM/2021/11/12/2849891923288064/2851166696439808/STEM/177abcea-3b43-412a-ac5f-27bcd77b297a.png)
21-22八年级上·江苏泰州·期中 查看更多[3]
江苏省泰州市海陵区第二中学附属初中2021-2022学年八年级上学期期中数学试题(已下线)期中难点特训(一)勾股定理与等腰(边)结合的压轴题-【微专题】2022-2023学年八年级数学上册常考点微专题提分精练(苏科版)(已下线)第09讲 平面直角坐标系(9大考点)-2022-2023学年八年级数学上学期考试满分全攻略(苏科版)
更新时间:2021-11-14 16:16:24
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解答题-作图题
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【推荐1】如图,在
中,点D,E分别在边
,
上,且
,点P与点C关于直线
成轴对称.
![](https://img.xkw.com/dksih/QBM/2021/5/12/2719643134885888/2721375677054976/STEM/42617f71-12fc-47cd-a2f9-f85d9abe7b80.png)
(1)求作点P;(要求:尺规作图,不写作法,保留作图痕迹)
(2)连接EP,若
,判断点P是否在直线
上,并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5eaffcd2070bfcb1955e2cab66c26c06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://img.xkw.com/dksih/QBM/2021/5/12/2719643134885888/2721375677054976/STEM/42617f71-12fc-47cd-a2f9-f85d9abe7b80.png)
(1)求作点P;(要求:尺规作图,不写作法,保留作图痕迹)
(2)连接EP,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f518abdd500d76a5c1b6499ff2ca7a08.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
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【推荐2】探索角的平分线的画法.
(1)画法1:利用直尺和圆规
请在图中用直尺和圆规画出
的平分线
;(不写画法不需证明,保留作图痕迹)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/21/1e6f2663-ffb3-4401-ade6-2555a191cde6.png?resizew=158)
(2)画法2:利用等宽直尺.
如图,将一把等宽直尺的一边依次落在
的两条边上,再过另一边分别画直线,两条直线相交于点O.画射线
,则射线
是
的平分线.这种角的平分线的画法依据的是______.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/21/b47f6dfa-30b7-4192-bbca-28db75c357e5.png?resizew=258)
A.
B.
C.
D.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c56ffc1f3244957d01e53013868fa76.png)
(3)画法3:利用刻度尺
已知:如图,在
的两条边上分别画
,
,连接
、
,交点为点O,画射线
.
求证:
是
的平分线.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/21/c4003098-b827-4764-9299-f7ad6245d4c6.png?resizew=162)
(4)画法4:利用你手里带有刻度的一块直角三角尺,设计一种与上述画法不同的角的平分线的画法.请在图中画出
的平分线
,写出画法,并加以证明.
(1)画法1:利用直尺和圆规
请在图中用直尺和圆规画出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/21/1e6f2663-ffb3-4401-ade6-2555a191cde6.png?resizew=158)
(2)画法2:利用等宽直尺.
如图,将一把等宽直尺的一边依次落在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/21/b47f6dfa-30b7-4192-bbca-28db75c357e5.png?resizew=258)
A.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cbfd199e0ba3e1ec7016a44454e7a3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec76570a0ddc83c103a4b77589d80701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a2ba04decd9d9204ec64d567af55721.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c56ffc1f3244957d01e53013868fa76.png)
(3)画法3:利用刻度尺
已知:如图,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d212c1709b8e72a055cf1b5381ef64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/21/c4003098-b827-4764-9299-f7ad6245d4c6.png?resizew=162)
(4)画法4:利用你手里带有刻度的一块直角三角尺,设计一种与上述画法不同的角的平分线的画法.请在图中画出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/21/797ee053-3c25-459f-b7a6-78245eb60238.png?resizew=151)
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解题方法
【推荐3】某数学兴趣小组在学习了尺规作图、等腰三角形和相似三角形的有关知识后,在等腰△ABC中,其中
,如图1,进行了如下操作:
![](https://img.xkw.com/dksih/QBM/2022/2/25/2923898906902528/2926080534659072/STEM/84ecff69-576e-49af-95be-2a4d456d3739.png?resizew=702)
第一步,以点A为圆心,任意长为半径画弧,分别交BA的延长线和AC于点E,F,如图2;
第二步,分别以点E,F为圆心,大于
EF的长为半径画弧,两弧相交于点D,作射线AD;
第三步,以D为圆心,DA的长为半径画弧,交射线AE于点G;
(1)填空;写出∠CAD与∠GAD的大小关系为___;
(2)①请判断AD与BC的位置关系,并说明理由.
②当
时,连接DG,请直接写出
___;
(3)如图3,根据以上条件,点P为AB的中点,点M为射线AD上的一个动点,连接PM,PC,当
时,求AM的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://img.xkw.com/dksih/QBM/2022/2/25/2923898906902528/2926080534659072/STEM/84ecff69-576e-49af-95be-2a4d456d3739.png?resizew=702)
第一步,以点A为圆心,任意长为半径画弧,分别交BA的延长线和AC于点E,F,如图2;
第二步,分别以点E,F为圆心,大于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
第三步,以D为圆心,DA的长为半径画弧,交射线AE于点G;
(1)填空;写出∠CAD与∠GAD的大小关系为___;
(2)①请判断AD与BC的位置关系,并说明理由.
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22088bb5a324a769b0232eb7d3015bc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24f92bdd55c1506dab2606654b4f842f.png)
(3)如图3,根据以上条件,点P为AB的中点,点M为射线AD上的一个动点,连接PM,PC,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b784fed7dbef4e2e77bf8be917b0c89c.png)
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【推荐1】如图,在平面直角坐标系中,点
,点
,点
,且a、b满足
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/17/ff84f8b5-c878-4f44-a687-19dfe3168bae.png?resizew=191)
(1)点A的坐标为______,点B的坐标为______;
(2)求证:
;
(3)若
,过点A作射线l(射线l与边BC有交点),过点B作
于点D,过点C作
于点E,过点E作
于点F交y轴于点G.
①求证:
;
②求点G的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d47b9fca60f683e4ed854fdb30c0a77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38145807a822e57d92d07ac8dd01b31f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fd4921fdebedad463d708690fe3cfa6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e97e74421ae2008581c703bdc90813c4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/17/ff84f8b5-c878-4f44-a687-19dfe3168bae.png?resizew=191)
(1)点A的坐标为______,点B的坐标为______;
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c10d461a7c0b86a2f09c2ea17f38260e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb0a2d7d40a6c0bf1fddb802db381689.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6411dec63998be60c272d5367e84a6a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa1ac7e4a2bcadf49838113ab6d95950.png)
①求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7e6363330b33ca9feda927e6ffd3088.png)
②求点G的坐标.
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【推荐2】如图,在平面直角坐标系中,已知抛物线
与x轴交于A,
两点,与y轴交于点C,点
在抛物线上,点P是抛物线上一动点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/10/1de95e7a-31b6-45ab-a612-6cd4af036dd0.png?resizew=217)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/11/cbfd022f-f49b-4d63-8040-4dbe0fb34315.png?resizew=197)
(1)求该抛物线的解析式;
(2)如图1,连接
,若
平分
,求点P的坐标;
(3)如图2,连接
,
,抛物线上是否存在点P,使
?若存在,请直接写出点P的坐标;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58d88bbd34102b55fa928e8ff83f0d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/316ba5cbb31299d683ac6c7dd795db85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2e60f98107a82434d300b04c0cc72b9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/10/1de95e7a-31b6-45ab-a612-6cd4af036dd0.png?resizew=217)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/11/cbfd022f-f49b-4d63-8040-4dbe0fb34315.png?resizew=197)
(1)求该抛物线的解析式;
(2)如图1,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed66570f697459aba9daa2eaf9460bcb.png)
(3)如图2,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c7ba2e37cd1201fde4df40579e4a69f.png)
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【推荐1】如图1,正方形
中,点
是直线
上一个动点,连接
,过点
作
于点
,过点
作
交
于点
,连接
、
.
在边
上,猜想:
①线段
和线段
的数量关系是______ ;
②线段
和线段
的位置关系是______ .
(2)如图
,点
在
延长线上,(1)中的猜想成立吗?请说明理由.
(3)已知
,当
时,直接写出
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e609409ed1cfd6b6a9b44f9fbd49f24.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3126c0a5dc3bd5ae4769a131e56b0b1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
①线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/167d31eb8432b5c0364316e5048c23dd.png)
②线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/167d31eb8432b5c0364316e5048c23dd.png)
(2)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
(3)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f08273d339dc5ddbb89aa67bb8205e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5acb7712bfb7ed112a4e137b0c53fc36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
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【推荐2】已知,在
中,
,
,
于点H,
平分
交
于点F,交
于点E.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/187ed8bd-8db3-4bc6-b571-9420c2b5692a.png?resizew=512)
(1)如图1,求证:
;
(2)如图2,在
外有一点D,分别连接
,当
时,求
的度数;
(3)如图3,在(2)的条件下,
,过点C作
交
延长线于点M,连接
、
,若
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff4744b427f036dfbc6db68c87cd5c54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fabb884dc5f9609de491245463bbe9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/826c728050e3378921442ace20269ef6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/187ed8bd-8db3-4bc6-b571-9420c2b5692a.png?resizew=512)
(1)如图1,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ac3d3b55561ec5d4acc242ecd1c7f41.png)
(2)如图2,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/515613c87c34a8ce4793f41032fa5236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a20cb14fea4a7cad4b7775a3dd67df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3981e7286d41960daf4e110c1c84e03a.png)
(3)如图3,在(2)的条件下,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59182f25fcf22afc79e28ded936de018.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a8217815edff97e8ea18b698de9c5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83042953e7f15e984b2da2ee9ca678d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/836effa5b91f7caa582394ba998612e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
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解答题-作图题
|
较难
(0.4)
【推荐1】(1)如图1,在AB直线一侧C、D两点,在AB上找一点P,使C、D、P三点组成的三角形的周长最短,找出此点并说明理由.
(2)如图2,在∠AOB内部有两点M、N,是否在OA、OB上分别存在点E、F,使彻E、F、M、N,四点组成的四边形的周长最短,找出E、F两点,保留作图痕迹.
(2)如图2,在∠AOB内部有两点M、N,是否在OA、OB上分别存在点E、F,使彻E、F、M、N,四点组成的四边形的周长最短,找出E、F两点,保留作图痕迹.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/18/52db39c4-2bb6-42d0-8463-2cd9b1f6851e.jpg?resizew=290)
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解答题-证明题
|
较难
(0.4)
【推荐2】我们把三角形的一条高线关于与其共顶点的内角平分线的对称线段所在直线叫做该三角形的倍角高线.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/82f2c22a-6006-422d-9ffc-7df6dfea94f8.png?resizew=325)
(1)如图1,
分别为
的高线和角平分线,若
为
的倍角高线.
①根据定义可得
,
(填写图中某个角);
②若
,求证:
为等腰三角形.
(2)如图2,在钝角
中,
为钝角,
,若
分别为
的高线和角平分线,倍角高线
交直线
于点E,若
,
,求线段
的长.
(3)在
中,若
,倍角高线
交直线
于点E,当
为等腰三角形,且
时,求线段
的长.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/82f2c22a-6006-422d-9ffc-7df6dfea94f8.png?resizew=325)
(1)如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d0317c700d704bf5d566998d23f4e7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
①根据定义可得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad75bdd17013af544fc97ab1dcecb873.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/802a939a9ab14a1a762a4275c9ec6899.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
(2)如图2,在钝角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9c0ee5c66b0efdb223b4ddd76908f85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c42ed2e5bd5a0f033e24008697bf4963.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d0317c700d704bf5d566998d23f4e7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddcaaf69feff70fa4ecbd75cc5dd04c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60634341a9603e24b2bbc6960abe3d31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
(3)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/977b8405822a0e77a916a08e5d303a16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af1389d663411aaf232fd509b08ed026.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e8f8b9fbb68c2ed710503a007eb4350.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
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