1 . 已知关于
的一元二次方程
的两根是一个矩形两邻边的长.
(1)
取何值时,方程有两个正实数根.
(2)当矩形的对角线长为
时,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324d9be4e6e9b2ee3bbd66594c9e847a.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(2)当矩形的对角线长为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2967337e3fcb228dded64ab0c41a17e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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2 . 设
的三边长为
,
,
,其中
,
是方程
的两个实数根.
(1)判断
是否为直角三角形?是说明理由.
(2)若
是等腰三角形,求
,
,
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/071a7e733d466949ac935b4b8ee8d183.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/a23e3a27703c60f6466ce2c28f152a8b.png)
(1)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/071a7e733d466949ac935b4b8ee8d183.png)
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3 . 阅读下面的材料,回答问题:
爱动脑筋的小明发现二次三项式也可以配方,从而解决一些问题.
例如:
;因此
有最小值是
.
(1)尝试:
,因此
有最大值是______.
(2)应用:有长为
米的篱笆,一面利用墙
墙的最大可用长度为
米
,围成一个长方形的花圃.能围成面积最大的花圃吗?如果能,请求出最大面积.
爱动脑筋的小明发现二次三项式也可以配方,从而解决一些问题.
例如:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25a424940bb28a12fe52f9ca1c80bbc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89470e52adc5679d354f5f30390d3b29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
(1)尝试:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bb57d9c3b0e3c5aa3d3f287c5d49c94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/189287dfd39da92d2eba97adb8f37832.png)
(2)应用:有长为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbbecbd7e92dcbe1766462fcf40066de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd995178601c2ad7b40f973d268c7bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c748e40ba21ac5063d3bccaa57ef278.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
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4 . 当
时,二次函数
有最大值
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a417f68c6538bfb63e729c047755b4ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1474926e4302dadfde4e3b9c3123589b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
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5 . 已知
,
是方程
的两个根,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4682de800665cf4d5f6f466d623bcdae.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bc2758dfd6206f74578d78aba5ccceb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4682de800665cf4d5f6f466d623bcdae.png)
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6 . 已知点
,
,
均在抛物线
上,下列说法中正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c5d57111dd825830d87e5a8ba28cf9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b5e695fbbd1a4c076757c2172e9ff5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/213632685641d1d75ce7e827db800b26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68846e796086eeff26e70135fdff94fb.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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7 . 已知
,
,则
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/909aed03a34ab0e77ee7a405d77c9834.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca0bb465e4fbaa41f973c55af3edc016.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c925be255ca736a53b24d13ddede1a86.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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8 . 已知一元二次方程
的两根
、
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37b0b55c3297ce66c96d1559d76971f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3000d101d000defcd047c09772e68b14.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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9 . 若
,则
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b43498cdea91037bd093c1100af4f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20d6fc9b90f370fbb27552876b650f8f.png)
A.![]() ![]() | B.![]() ![]() | C.![]() ![]() | D.![]() ![]() |
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10 . 把
分解因式的结果是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a29e54ba76149d87d5891156e34b76ab.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次