解题方法
1 . 设
,
,求证下列不等式:
(1)
;
(2)
;
(3)
;
(4)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/061813f1ec633c5c4c393c4de7938322.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/216682504182873f78cc43e6e46799cb.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f0274fb77878866cc088d719a060e3f.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83d2e0a4dc2e7a7e72c1620374e038b8.png)
(4)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f9fc73d3810e2573cfc02488c41baab.png)
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2 . 对任意三个正实数
,
,
,求证:
,当且仅当
时等号成立.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ef3052cd1be7641eb559c5d7ed142cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44acc0ee22dc4b7750e8be825e7c1355.png)
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3 . 设a,b为正数,证明下列不等式成立:
(1)
;
(2)
.
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aa23408bcc9f6200f22a310e5f2569a.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7efecdd67f1088510886e88b80263bd8.png)
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21-22高一·湖南·课后作业
解题方法
4 . 设
,
为正实数,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc98f6e2b1d41bc552c083979f53a83d.png)
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21-22高一·湖南·课后作业
解题方法
5 . 证明下列不等式,并讨论等号成立的条件:
(1)若
,则
;
(2)若
,则
;
(3)若
,则
;
(4)若
,则
;
(5)对任意实数
和
,
.
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66d87d567e5ccc0d31d063609810e5cc.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87a655d6935ae3f646e17ff72bc213e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b20f398d8772984301018f832966b14.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6343069217cd6d8dd32446da428dae46.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73f23c87e770c3cc61bad09643926ae6.png)
(4)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eae9ba258299eb489b490594397e23c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46973ec354692c420913269bc23a8035.png)
(5)对任意实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91a470f596a01c8273f55b9fb394b0f6.png)
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21-22高一·湖南·课后作业
6 . 下列结论是否成立?若成立,试说明理由;若不成立,试举出反例.
(1)若
,则
;
(2)若
,则
;
(3)若
,则
.
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39d5f0d374837655cc286d326305da36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/759c09917e5728d75bf5cfdb5b4a807f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39d5f0d374837655cc286d326305da36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5761e8fbc832afcfce07dab1d4dfc385.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94ed37ee7432002cd0e0978b2012e184.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37006891004d02050e7c57db20af3981.png)
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20-21高一·江苏·课后作业
7 . 甲、乙两同学分别解“设
,求函数
的最小值”的过程如下:
甲:
,又
,所以
.
从而
,即y的最小值是
.
乙:因为
在区间
上的图象随着x增大而逐渐上升,即y随x增大而增大,所以y的最小值是
.
试判断谁错,错在何处?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4318a47d7e83d587e74bab4d3d1f6883.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2751c5819303b8e60add2356bd7c808b.png)
甲:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7833f1728bed812cd05321fdae104d47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2fb40a36a293471742ce75f6b9635b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca195cc5a87ca48a861db1d86f5dbf33.png)
从而
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e35510c7852e4f698522f808de475984.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95bacae35b6e16a0a33c2bdc6bc07df7.png)
乙:因为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2751c5819303b8e60add2356bd7c808b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeb49dbba01c4ff5f686ffc8828351b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/209a95bdee4d5e56dd0e165d3e794d18.png)
试判断谁错,错在何处?
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20-21高一·江苏·课后作业
8 . 如图,我国古代的“弦图”是由四个全等的直角三角形围成的.设直角三角形的直角边长为a,b,根据图示,大正方形的面积与四个小直角三角形的面积之和存在不等关系,用a,b表示这种关系.
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20-21高一·江苏·课后作业
9 . 证明:
(1)
;
(2)
.
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d6e89ff670f9a10eb087a02051f3a50.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8c573bd16158492f3c6533261d2188b.png)
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20-21高一·江苏·课后作业
10 . 设x,y为正数,比较
与
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16f0b84ee4ed90face0993d4f4dda379.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2696d72704a8274a995063527e89d38f.png)
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