1 . 探索研究:
(1)比较下列各式的大小.(用“
”、“
”或“
”连接)
①
; ②
;
③
; ④
.
(2)通过以上比较,请你分析、归纳出当a,b为有理数时,
与
的大小关系.
(3)根据(2)中得出的结论,当
时,x的取值范围是 ;当
,
,则
.
(1)比较下列各式的大小.(用“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ff7942da6c3fc4005256fb1458557c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392cdb9d30684cce244bef94b8d861b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6706fe00b4e231e62d9ecbec567d526b.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bd825724f307ff0ac97f3142a3ab303.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/928e6768882cb34775f72fc0bca684d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da0b7d902ffea2e2d44710a6da72db66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05524a36ed26b65b2ed5ff47dd73fa4d.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5aa70793de00a99c7fda491c61173f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f15076aec21e151e7e017340a71dce4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5956b5db7c0beafc00de12e21b289660.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/debf10cc2d717a08077109b4617017f7.png)
(2)通过以上比较,请你分析、归纳出当a,b为有理数时,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed4bd51878a0eae716791cdfa4312bf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b33ceacb7836ccd98815e08a20cd2be.png)
(3)根据(2)中得出的结论,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/127b560e544e239c8525fb27b6b0ac14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eac884109321348cb2378d25589bfe36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c0839ea459559c6efcb780defbd4edf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19b7daadaea74c1a9d8f97fd0b4086f1.png)
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2 . 【阅读】要想比较a和b的大小关系,可以进行作差法,若
,则
;若
,则
;若
,则
.
,在实数范围内比较大小:
______
(填“>”、“<”或“=”);
【拓展】(2)已知甲、乙两个长方形纸片,其边长如图11所示
,面积分别为
和
,用含m的式子表示
和
,并用作差法比较
与
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/481ee0d1e39e92a4732eea90225eb94c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432d77fe5ad3032d59a237dd94c8a638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4f7bea84b44a1dd19c1d3682688c7b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6a46e678bf9d2df5ad4c782b3dc22f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/697c3d4b11fc2ae913cc27b6b63fc199.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c400a615a16a1662de98dfb4e49d58d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8cc0b4997cae4d8aec791a1d3923314.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/272f801e4afe574af5706f49868941d7.png)
【拓展】(2)已知甲、乙两个长方形纸片,其边长如图11所示
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b96256957fd38dfdb77df75ff4ce5a3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68c7bb6fb4b26508ec5f6f62ee846cb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c9e60e949f1626a58a8c0eb756f580d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68c7bb6fb4b26508ec5f6f62ee846cb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c9e60e949f1626a58a8c0eb756f580d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68c7bb6fb4b26508ec5f6f62ee846cb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c9e60e949f1626a58a8c0eb756f580d.png)
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名校
3 . 若点
都在一次函数
图像上,则
与
的大小关系是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e7636d565db2ec1cc7a78b60a49531d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9bd144e0e96e4236a14523e0729cacb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54015ff5b49e3283901da1291b6b921d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46f6872ffb1934339c53c2c2282d5889.png)
A.![]() | B.![]() | C.![]() | D.无法比较大小 |
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2023-12-09更新
|
216次组卷
|
3卷引用:清单14 一次函数的图象与性质(2个考点梳理+20种题型解读+提升训练)-2023-2024学年八年级数学上学期期末考点大串讲(苏科版)
(已下线)清单14 一次函数的图象与性质(2个考点梳理+20种题型解读+提升训练)-2023-2024学年八年级数学上学期期末考点大串讲(苏科版)辽宁省沈阳市皇姑区第四十三中学2023-2024学年八年级上学期期中数学试题四川省达州市达川区2023-2024学年八年级上学期期末数学试题
4 . 探索研究:
(1)比较下列各式的大小(用“
”或“
”或“
”连接)
①
;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b419ab24433dc3e86c8c3d4c861478d.png)
②
;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a7ee843983c5e3f5edb4d752301631b.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/915f7d6bfd6663c2952aa497d1888e48.png)
(2)通过以上比较,请你分析、归纳出当
、
为有理数时,
与
的大小关系.
直接写出结论即可)
(1)比较下列各式的大小(用“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ff7942da6c3fc4005256fb1458557c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392cdb9d30684cce244bef94b8d861b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6706fe00b4e231e62d9ecbec567d526b.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b03f3bbb11c56121bdf4427200161db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6b276b19893de96c02c846f19a0489a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b419ab24433dc3e86c8c3d4c861478d.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94a51e6f8a1ff97502d437960cb82054.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7554e70935fd9c455fa9d6923bfd2010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a7ee843983c5e3f5edb4d752301631b.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcf280d7281d24a3f5f44170eecab000.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/915f7d6bfd6663c2952aa497d1888e48.png)
(2)通过以上比较,请你分析、归纳出当
![](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/fd7ba15d9d1b6a248b48ac375b042269.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e7fd6cdc1a06fe5dee7ca6fc7b1907f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d71379442f28c038d367d49422cf90.png)
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5 . 【阅读理解】我们在分析解决某些数学问题时,经常要比较两个数或代数式的大小,解决此类问题时一般要进行转化,其中“作差法”就是常用的方法之一.其依据是不等式(或等式)的性质:若
,则
;若
,则
;若
,则
.
例:已知
,
,其中
,求证:
.
证明:
,
因为
,所以
,故
,
【新知理解】
(1)比较大小:
______
.(填“
”,“
”,“
”)
【问题解决】
(2)甲、乙两个平行四边形,其底和高如图所示(a为正整数),其面积分别为
,
.请比较
,
的大小关系.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/17/7a49d32d-c18b-40ce-b775-4737bc0ad719.png?resizew=351)
【拓展应用】
(3)请用“作差法”解决下列问题:
初中生小明暑假准备去游泳,已知游泳馆在暑假期间对学生优惠开放,游泳票为30元一张,有A,B两种方案可供选择,A方案:每次按原价打9折收费;B方案:前5次按照原价收费,从第6次起每次打8折.请问小明选择哪种方案更合算?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdb9873dfaf15e799fa6fb0128433725.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b21208364124b5c477b2ff8df1c2e8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42498f6e0fc9a61c9857b70a87f02c5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b9d5aaaceaa3ac514d17fcfefbf9b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd1b24be6fb606863a3faca43c281063.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43a5abe56c019ac914e1fcde1865a747.png)
例:已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1eb8b6c81b787e1b5b979211dd48e04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68f2c355b245cd7679fcc55ad849845d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2958030ec9d7543dda1f529593a915e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f8f97cf2fc2d0676d6df01ff9759611.png)
证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92079d1a6909a0f4eb560843efd53e39.png)
因为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2958030ec9d7543dda1f529593a915e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93c8e331b8f54975c6d188c23267bf7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f8f97cf2fc2d0676d6df01ff9759611.png)
【新知理解】
(1)比较大小:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95e26ea0261f2b67983b07b8d0bb8bf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/526b7feed403e005b0a04671bcb70c8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392cdb9d30684cce244bef94b8d861b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6706fe00b4e231e62d9ecbec567d526b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ff7942da6c3fc4005256fb1458557c0.png)
【问题解决】
(2)甲、乙两个平行四边形,其底和高如图所示(a为正整数),其面积分别为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/17/7a49d32d-c18b-40ce-b775-4737bc0ad719.png?resizew=351)
【拓展应用】
(3)请用“作差法”解决下列问题:
初中生小明暑假准备去游泳,已知游泳馆在暑假期间对学生优惠开放,游泳票为30元一张,有A,B两种方案可供选择,A方案:每次按原价打9折收费;B方案:前5次按照原价收费,从第6次起每次打8折.请问小明选择哪种方案更合算?
您最近一年使用:0次
6 . “若
,则
”.根据这一等式的性质可将幂的运算逆向应用,如
.在解题过程中,根据算式的结构特征,逆向运用幂的运算法则,常可化繁为简,化难为易,使问题巧妙获解.
(1)
______;
(2)若
,求m的值;
(3)比较大小:
,
,则
的大小关系是什么?(提示:如果
,
为正整数,那么
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15d00e896ece0bec6845cdf25235bcbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6204117a2863d2c59144d90cc0620905.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1ae7530daa942a76abbcea6e720ecdf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e80bff2a152a51b587760f16e2ca0ea3.png)
(3)比较大小:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3260dc4320df980b2d7767a349cb0b63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6867373a2169a9a2a51867410aa1998d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e676f49304c874f9e48acd8b22e194b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da5d9e1f33b559181e4ca4e6c85ccc03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc46672e771f28e7b20f6ad392cfd084.png)
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名校
7 . 根据数学研究对象本质属性的共同点和差异点,将事物分类,然后对划分的每一类进行研究的方法叫做“分类讨论”方法.
(1)在探究
的大小关系的过程中,我们根据
,
的符号和绝对值的大小进行分类归纳.下列
,
的取值中:①
,
;②
,
;③
,
;④
,
;⑤
,
;⑥
,
;⑦
,
;⑧
,
;⑨
,
.可以代表大小关系不同种类的取值组合是 _________ .
A.①②③④⑦⑧⑨ B.①②③④⑤⑥⑦
C.②③④⑤⑥⑦⑨ D.①②③④⑥⑦⑧
(2)通过以上比较,请你归纳出当
,
为有理数时,
与
的大小关系.
(3)根据(2)中得出的结论,当
时,
的取值范围是 _________ ;整数
,
,
,
满足
,
,则
_________ .
(1)在探究
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed4bd51878a0eae716791cdfa4312bf0.png)
![](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/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb8e1dd8da540badcb9a8f427c5b202e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82986ab38a4ae58593191ccae2a44f62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e9222ffc26c0e6bfbf252ab5d8a520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9756b95e078670ea02a4b3d66f0dc7c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b4d795709b0abcf47bceec2250f2f9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bd2215e5cdeb3f6b0b7929a4a05ba65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a88e026f5e5a7782144513c691259159.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc64eaf4cd6737b000b28f1fcdd16c4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f22a4a0dd7307a1323d25331e60782d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a3c442579603164f3fc19458677d307.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa4c355f11471a38f5583a434a1ddeb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5032113438f38f1b2d7b270e803d1837.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab839d8569171afab5ed55c22013aa72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/143b917df0520097be222accbddf9394.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f77d5c5fa06ec748e956e86c49cafb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04a7551d073a061eef22c9e127d6deeb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52dffb3a20eb46a7bf05e33bde5f4f7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b73de06507874a74422b61b2993877f.png)
A.①②③④⑦⑧⑨ B.①②③④⑤⑥⑦
C.②③④⑤⑥⑦⑨ D.①②③④⑥⑦⑧
(2)通过以上比较,请你归纳出当
![](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/ed4bd51878a0eae716791cdfa4312bf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b33ceacb7836ccd98815e08a20cd2be.png)
(3)根据(2)中得出的结论,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba09fa4a65080d57dd53934dc0047ef8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f8da657f6888a7c6caad191368262f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72d93cc443acfb5466619be5bbcacc8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19b7daadaea74c1a9d8f97fd0b4086f1.png)
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8 . 已知代数式
和
.
(1)比较
与
的大小(用等号或不等号填空)
①当
时,计算得:
_________
;
②当
时,计算得:
_________
;
③当
时,计算得:
_________
;
(2)根据(1)的计算结果猜想
和
的大小关系,并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24359c457cbf414783156b10118d2342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aee45a9563cab3bda2bb80aca1f8c86.png)
(1)比较
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24359c457cbf414783156b10118d2342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/def40fffaed331cb61d4d924352ac69a.png)
①当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd876a2ed79c64bacc3e64b8ee92735e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24359c457cbf414783156b10118d2342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aee45a9563cab3bda2bb80aca1f8c86.png)
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aed39f5aca78934fb383402433fe549.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24359c457cbf414783156b10118d2342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aee45a9563cab3bda2bb80aca1f8c86.png)
③当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e94f16d5ed858699bfea5039a7bf8ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24359c457cbf414783156b10118d2342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aee45a9563cab3bda2bb80aca1f8c86.png)
(2)根据(1)的计算结果猜想
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24359c457cbf414783156b10118d2342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aee45a9563cab3bda2bb80aca1f8c86.png)
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名校
9 . 我们在分析解决某些数学问题时,经常要比较两个数或代数式的大小,解决问题的策略一般都是进行一定的转化,其中“作差法”就是常用的方法之一.作差法:就是通过作差、变形,利用差的符号确定它们的大小,即要比较代数式A、B的大小,只要算
的值,若
,则
;若
,则
;若
,则
.
(1)请用上述方法比较下列代数式的大小(用“>、=、<”填空):
①
______
;
②若
,则
______
;
(2)试比较与
与
的大小,并说明理由;
(3)图1是边长为4的正方形,将正方形一组对边保持不变,另一组对边增加
得到如图2所示的长方形,此长方形的面积为
;将正方形的边长增加a,得到如图3所示的大正方形,此正方形的面积为
;则
与
的大小关系为:
______
;
,
,试运用上述方法比较M、N的大小,并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e9e460c144f7a2141d2df0308b125f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d417bb42ad05a3f1d7720352be1a01f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca51be437b1a97ca92aa1159ab71102c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/452ec2a5f08bb746727494536710d115.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46a70d32c64918aa4d1d9d3ce0bdbf7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c8228bc073af40562d89e8acaa47412.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98d0b9c0c01b49be6e08a111568f77f4.png)
(1)请用上述方法比较下列代数式的大小(用“>、=、<”填空):
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1b8d3f7a166ff5db92d9ee0014a960d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8314e2f98928b76d7fb74b09283f3db.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca24341509c05e672999202f2df0ebaf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8cc0b4997cae4d8aec791a1d3923314.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a881309775c3b6a9f4ed408838666342.png)
(2)试比较与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ec151b5e23f86a12a2c2f84f79e2be6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bc195aaf8c50791636d980e75fc19ad.png)
(3)图1是边长为4的正方形,将正方形一组对边保持不变,另一组对边增加
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1efa45b6ea4a163cf0963ed2602cb4de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42c560e45f806ba9ed19fd3e82eee66f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dfb499879810be72bd00521337aea89.png)
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2023-08-16更新
|
219次组卷
|
4卷引用:江苏省连云港市东海县2022-2023学年七年级下学期期末数学试题
江苏省连云港市东海县2022-2023学年七年级下学期期末数学试题江苏省宜兴市树人中学教育集团2023-2024学年九年级上学期第一次调研数学试题(已下线)七年级期末考前必刷卷-2023-2024学年七年级数学下学期期末考点大串讲(苏科版)广东省茂名市高州市十二校联考2023-2024学年九年级上学期期中数学试题
10 . 七年级上册课本第7页“试一试”,用16米长的篱笆围成长方形的生物园饲养小兔.在这个活动中,我们已经感受到,周长一定的长方形,长宽越接近,面积越大.
图1是用两根同样长的铁丝分别围成的一个长方形和一个正方形,设长方形的宽为
,长比宽多
.
(1)用含
、
的代数式表示正方形的边长
(2)七年级下册课本第77页的“数学实验室”中有这样一个操作:在边长为
正方形纸片上剪去一个边长为
的小正方形,沿图中虚线剪开,将阴影部分拼成一个长方形,如图2.在此操作中发现:图①中的大正方形周长与图②的长方形的周长相等.请你仿照这个操作,通过剪拼图1,比较图1中的正方形与长方形的面积大小,并画出图形;
(3)由(2),我们已经发现周长一定时长方形与正方形面积的大小关系,请你利用图1通过计算进行证明.
图1是用两根同样长的铁丝分别围成的一个长方形和一个正方形,设长方形的宽为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f93a232c88870d213a7b74a796a1ff4b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/21/1e6b3629-c388-42ec-8258-4e5d2575e8ca.png?resizew=537)
(1)用含
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(2)七年级下册课本第77页的“数学实验室”中有这样一个操作:在边长为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5917d49e73db5c07f7aea209b1fbcab8.png)
(3)由(2),我们已经发现周长一定时长方形与正方形面积的大小关系,请你利用图1通过计算进行证明.
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