已知
.
(1)若
与
均为正数,求
的最大值;
(2)若
与
均为负数,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5acd1467c10c7ff14caca53feea7a540.png)
(1)若
![](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/18f0281e6bbdbe08beeccb55adf84536.png)
(2)若
![](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/20aed978313b6896ef5a1b01e8aaf6be.png)
更新时间:2023-12-22 11:11:38
|
相似题推荐
解答题-问答题
|
较易
(0.85)
解题方法
【推荐1】(1)已知
,求
的最小值;
(2)已知
,
,
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fde64f4d3c38e43fbdee24eadc4b0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45b398e30b66e74b63086e9b3531090c.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/061813f1ec633c5c4c393c4de7938322.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2436951e9a6f5ca0fc0ae65b9d787119.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f29d5f376c75c41ae6af0c8a8565449.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
解题方法
【推荐2】如图所示,有一批材料长为24 m,如果用材料在一边靠墙(墙足够长)的地方围成一块矩形场地,中间用同样的材料隔成两个面积相等的矩形,那么围成的矩形场地的最大面积是多少?
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/d1ffc358-4720-45ac-ba7e-3fce2c290046.png?resizew=191)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
名校
解题方法
【推荐1】有这样一道利用基本不等式求最值的题:
已知
且
求
的最小值.
小明和小华两位同学都“巧妙地用了
”,但结果并不相同.
小明的解法:由于
所以![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1aa5eb4249cc659809767bb1650cfbe.png)
而
那么
则最小值为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/474bd808b81bce2d61dc8b95d0c740b6.png)
小华的解法:由于
所以![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11c9fc2869dcc1ae6d913b5db300f43c.png)
而
则最小值为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/172681503b639df2b7dac358af9e9b06.png)
(1)你认为哪位同学的解法正确,哪位同学的解法有错误?
(2)请说明你判断的理由.
已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c34c590f48c84fe471d1af522c343c59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d575bf340fd6486b3173ba6adc7d027f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e85107c8abd4a977590d7c038ed127a.png)
小明和小华两位同学都“巧妙地用了
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5be97cd1c7111b654d87d8fbb63b6a84.png)
小明的解法:由于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d575bf340fd6486b3173ba6adc7d027f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1aa5eb4249cc659809767bb1650cfbe.png)
而
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c869e5b4206749e1bdac5d6a87353276.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83ad92003a4e0e1544d98a8748f20711.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/474bd808b81bce2d61dc8b95d0c740b6.png)
小华的解法:由于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d575bf340fd6486b3173ba6adc7d027f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11c9fc2869dcc1ae6d913b5db300f43c.png)
而
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a232ed285d1569176a42ea0b6bae746.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/172681503b639df2b7dac358af9e9b06.png)
(1)你认为哪位同学的解法正确,哪位同学的解法有错误?
(2)请说明你判断的理由.
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
名校
解题方法
【推荐2】已知
.
(1)若m=0,求x+y的最小值;
(2)若
,求xy的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddd13ac8eaf82bcc94a84ebb6b81f27d.png)
(1)若m=0,求x+y的最小值;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1849804607cb196eb466712274be985a.png)
您最近一年使用:0次