职高高一数学《不等式》章节练习题.doc

<p>数学《不等式》章节练习题
班级： &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 姓名： &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
一． 选择题：（共8题，每题3分，共24分）
（ &nbsp; &nbsp; &nbsp;）1. 若a&gt;0，ab&lt;0，则 a.=&quot;&quot; b=&quot;&quot;&gt;0 &nbsp; &nbsp; &nbsp; &nbsp; B. b≥0 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;C. b&lt;0 d.=&quot;&quot; r=&quot;&quot; 2.=&quot;&quot; -2x=&quot;&quot;&gt;-6的解集为
A. &nbsp; &nbsp; &nbsp;B. &nbsp; &nbsp; &nbsp; &nbsp;C. &nbsp; &nbsp; &nbsp; D.
（ &nbsp; &nbsp; &nbsp;）3. 不等式（x+1）（x-3）&gt;0的解集为
A. &nbsp; &nbsp; &nbsp;B. &nbsp; &nbsp; &nbsp; &nbsp;C. &nbsp; &nbsp; D.
（ &nbsp; &nbsp; &nbsp;）4. 不等式x（x+2）&lt;0的解集为
A. &nbsp; &nbsp; &nbsp;B. &nbsp; &nbsp; &nbsp; &nbsp;C. &nbsp; &nbsp; D.
（ &nbsp; &nbsp; &nbsp;）5. 若，且b&lt;0，则下列各式中成立的是 a.=&quot;&quot; b=&quot;&quot;&gt;0 &nbsp; &nbsp; &nbsp; &nbsp;B. a+b&lt;0 c.=&quot;&quot; d.=&quot;&quot; b-a=&quot;&quot;&gt;0
（ &nbsp; &nbsp; &nbsp;）6.下列不等式中成立的是
A. x2&gt;0 &nbsp; &nbsp; &nbsp; &nbsp; B. x2+x+1&gt;0 &nbsp; &nbsp; &nbsp;C. x2-1&lt;0 d.=&quot;&quot; -a=&quot;&quot;&gt;a
（ &nbsp; &nbsp; &nbsp;）7.下列不等式与x&lt;1同解的是 a.=&quot;&quot; -2x=&quot;&quot;&gt;-2 &nbsp; &nbsp; &nbsp; B. mx&gt;m &nbsp; &nbsp; &nbsp; &nbsp; C. x2(x-1)&gt;0 &nbsp; &nbsp; D. (x+1)2(1-x)&gt;0
（ &nbsp; &nbsp; &nbsp;）8.不等式&lt;1的解集为
A. R &nbsp; &nbsp;B. &nbsp; &nbsp; &nbsp; &nbsp;C. &nbsp; &nbsp; &nbsp; D.
（ &nbsp; &nbsp; ）9、若且，则下列不等式一定成立的是
（A） （B） （C） &nbsp; （D）
（　 &nbsp; &nbsp;　）10、 已知a，b，c，d∈R，若a＞b，c＞d，则 &nbsp;
(A) a－c＞b－d &nbsp; (B) a＋c＞b＋d &nbsp; (C) ac＞bd &nbsp; 　(D)
( &nbsp; &nbsp; &nbsp; &nbsp;)11、若a＞b＞0，给出下列不等式，其中正确的是
(A)ac＞bc &nbsp; &nbsp;(B)＞ &nbsp; &nbsp;(C) &nbsp; &nbsp; &nbsp;(D)
（ &nbsp; &nbsp; &nbsp; ）12、若，则下列不等式中正确的是
　　 &nbsp; &nbsp; &nbsp; (A)b2＜a2 &nbsp; &nbsp; &nbsp; &nbsp;(B)＞ &nbsp; &nbsp; &nbsp; (C)-b＜-a &nbsp; &nbsp; &nbsp;(D)a-b＞a+b
（ &nbsp; &nbsp; &nbsp;）13、若，则
A． &nbsp; &nbsp; B． &nbsp; &nbsp; C． &nbsp; &nbsp; &nbsp;D．
( &nbsp; &nbsp; &nbsp;)14、已知不等式的解集是，则实数a的取值范围是
　　 &nbsp; (A) a＞2 &nbsp; &nbsp; &nbsp; &nbsp;(B)a＜-1 &nbsp; &nbsp; &nbsp; &nbsp;(C)a≥2 &nbsp; &nbsp; &nbsp; (D)a≤-1

(　　 )15．不等式＞0的解集为{x|＜x＜}，则a，c的值为
A.a＝6，c＝1　B.a＝－6，c＝－1 &nbsp; C.a＝1，c＝1 &nbsp;D.a＝－1，c＝－6
（ &nbsp; &nbsp; &nbsp;）16、已知，那么有 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
A．最大值4 &nbsp; &nbsp; &nbsp; &nbsp; B．最小值4 &nbsp; &nbsp; &nbsp; &nbsp;C．最大值2 &nbsp; &nbsp; &nbsp; &nbsp;D．最小值2
（ &nbsp; &nbsp; &nbsp;）17、设且，则下列各数中最大的是
A、 &nbsp; &nbsp; &nbsp; &nbsp; B、2 &nbsp; &nbsp; &nbsp; &nbsp;C、2 &nbsp; &nbsp; &nbsp; D、
( &nbsp; &nbsp; &nbsp;)18、函数（）有
A．最大值1 &nbsp; &nbsp; &nbsp; &nbsp; B．最小值1 &nbsp; &nbsp; &nbsp; C．最大值2 &nbsp; &nbsp; &nbsp; &nbsp;D．最小值2

二．填空题：（共18空，每空2分，共36分）
1. 若a&lt;-2a,则a a=&quot;&quot;&gt;2a，则a &nbsp; &nbsp;0.

2. 若a&gt;b,c+1&lt;0,则ac 1=&quot;&quot; bc=&quot;&quot; ac2=&quot;&quot; bc2.=&quot;&quot; 3.=&quot;&quot; a2=&quot;&quot; 0.=&quot;&quot; 4.=&quot;&quot; .=&quot;&quot; 5.=&quot;&quot;&gt;0的解集是 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ；（用区间表示）
不等式&lt;3解集是 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .（用区间表示）
6. 如果x-3&lt;5，那么x&lt; -2x=&quot;&quot;&gt;6，那么x&lt; &nbsp; &nbsp; ；(运用了性质 &nbsp; &nbsp; ).
7. 不等式x2+6x+9≥0的解集为 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .
8、若1＜α＜3，－4＜β＜2，则α－β的取值范围是________．
9．不等式＞0的解集是__________________.
10、设，则（填“＜”或“＞”）
11、不等式 对一切实数x都成立，则实数a的取值范围是__________ &nbsp; ______

三．解答题：（共10题，每题4分，共40分）
1.解不等式：
(1) 4x+1≤5 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(2) 3x+2≥5

(3) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(4)

(5) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(6)

(7) 3x2-2x-1≥0 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;(8) -x2-2x+3≥0

2.比较大小：
（1）（x+1）(x+5)与(x+3)2 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (2) (x2+1)2与x4+x2+1

3、关于x的一元二次=0有两个不相等的实数根，试求m的范围？

4、如图，动物园要围成相同的长方形虎笼四间，一面可利用原有的墙，其他各面用钢筋网围成.
现有可围36 m长网的材料，每间虎笼的长、宽各设计为多少时，可使每间虎笼面积最大？

&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;

5、要用6米长的材料造一个窗框，上窗两格，其高度为下窗高的1/2，
问怎样设计采光面积最大？（如右图所示）

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