范文一:2018年郑州一模试卷及答案
2017-2018学年上学期期末考试
九年级数学试题卷
一、选择题(共 10题,每题 3分,共 30分) 1、下列各数中,最小的数是( ) A . 2018- B . 2018 C . 20181-
D . 2018
1
答案:A
2、下列计算正确的是 ( )
A. 2222a a a =? B. 428a a a =÷ C()22
42a a =- D()
52
3
a a =
答案:C
A . 4108. 2? B . 5108. 2? C . 81028. 0? D . 4
1028?
答案 :B
5.如图,已知△ ABC (AC
A . B C. D .
答案 :D
6. 若干盒奶粉摆放在桌子上, 如图是其中一盒奶粉的实物以及这若干盒奶粉所组成的几何体 从正面、左面、上面所看到的图形,则这些奶粉共有( )盒。
A.3 B.4 C.5 D.不能确定
从正面看 从左面看 从上面看
答案 :B
7.班级元旦晚会上,主持人给大家带来了一个有奖竞猜题,他在一个不透明的袋子中放了 若干个形状大小完全相同的白球, 请大家想办法估计出袋中白球的个数, 数学课代表小明是 这样估计出来的,他先现往袋子中放入了 10个形状大小与白球相同的红球.混匀后从袋子 中随机摸出了 20个球,发现其中有 4个红球.如果设袋中有白球 x 个,则根据小明的方法 用来估计袋中白球个数的方程是( ) A .
10420x = B. 101
20
x = C .
1014x = D . 104
1020
x =+ 答案 :D
8. 如图,已知一次函数 y=kx+b(k , b 为常数,且 k ≠ 0) 的图象与 x 轴相交于点 A (3, 0) , 若正比例函数 y=mx(m 为常数, 且 m ≠ 0) 的图象与一次函数的图象相交于点 P ,且点 P 的横 坐标为 1,则关于 x 的不等式(k ﹣ m ) x+b<0的解集为 a.="">0的解集为><1 b.="" x="">1 C. x<3 d.="" x="">3 答案 :B
9.若关于 x 的一元二次方程(k+1) x 2
+2(k+1) x+k﹣ 2=0有实数根,则 k 的取值范围在数 轴上表示正确的是( ) A . B. C. D.
答案 :A
10.如图一段抛物线:y=﹣ x (x ﹣ 3) (0≤ x ≤ 3) ,记为 C 1,它与 x 轴交于点 O 和 A 1;将 C 1绕 A 1旋转 180°得到 C 2,交 x 轴于 A 2;将 C 2绕 A 2旋转 180°得到 C 3,交 x 轴于 A 3
,如此进行
下去,直至得到 C 10,若点 P (28, m )在第 10段抛物线 C 10上,则 m 的值为( )
A . 1
B . -1 C . 2
D .﹣ 2
答案 :D
二、填空题:(把正确的答案写在横线上,每题 3分,共 15分) 11. 计算
()=+
91-0
π。
答案:4
12.2017年 12月 31日晚,郑东新区如意湖文化广场举行了“文化跨年夜、出彩郑州人”的 跨年庆祝活动, 大学生小明和小刚都各自前往观看了演出, 而且他们两人前往时选择了以下 三种交通工具中的一种:共享单车、 公交、地铁,则他们两人选择同一种交通工具前往观看 演出的概率为 。
答案:
3
1
13. 已知三个边长分别为 1、 2、 3的正三角形从左到右如图排列,则图中阴影部分面积 为 。
答案:
34
5
14. 某果园有 100棵橘子树,平均每一棵树结 600
个橘子.根据经验估计,每多种一棵树,
平均每棵树就会少结 5个橘子. 设果园增种 x 棵橘子树, 果园橘子总个数为 y 个, 则果园里 增种 棵橘子树,橘子总个数最多. 答案:10
15. 如图, BC ⊥ y 轴, BC
OA=
, AB=3,∠ OAB=45°, E 、 F 分别是线段 OA 、 AB 上的两动点,且始终保持
∠ DEF=45°,将△ AEF 沿一条边翻折,翻折前后两个三角形组成的四边形为菱形,则线段 OE 的值为 ___________
答案:3 3
2 3
三、解答题(共 8道题,共 75分)
16. 先化简,再求值:22444
22x x x x x x ??+++÷ ?
--??
,其中 x 的值从不等式组 1213x x -??-≤? 的 整数解中选取 .
【解】 :原式 =()2
22422x x x x x +??-÷
?--?? =
()()()
2
222
2x x x
x x -+?-+
=
2
x x + 解不等式组 1
213
x x -??
-≤? ,得
∴该不等式组的整数解为 0,1,2
当 0x =或 2时,原式无意义 ∴1x =
当 1x =时,原式 =
11123
=+ 17. 郑州市大力发展绿色交通,构建公共绿色交通体系,
“共享单车”的投入使用给人们的出
行带来便利,小明随机调查了若干市民租用共享单车的骑车时间 t (单位:分) ,将获得的 数据分成四组,绘制了如图统计图,请根据图中信息,解答下列问题:
(1)这次被调查的总人数是多少? (2)补全条形统计图
(3)在扇形统计图中,求表示 A 组(t ≤ 10分)的扇形圆心角的度数, .
(3)如果骑共享单车的平均速度为 12km/h,请估算,在租用共享单车的市民中,骑车路程 不超过 6km 的人数所占的百分比. 【解】 (1) 50(人)
(2) C 组人数为 50﹣(15+19+4) =12(人) ,
补全条形图如下:
(3)表示 A 组的扇形圆心角的度数为 360°×
=108°,
(4)路程是 6km 时所用的时间是:6÷12=0.5(小时) =30(分钟) , 则骑车路程不超过 6km 的人数所占的百分比是:
×100%=92%.
18. 如图 , 在 ? ABCD 中 , 点 O 是边 BC 的中点
, 连接 DO 并延长 , 交 AB 延长线于点 E, 连接 BD,EC. (1)求证 :四边形 BECD 是平行四边形 ; (2) 当 =
∠BOD
(3)若 ?
=∠50A , 则当 =
∠BOD
解:(1)证明 :∵四边形 ABCD 为平行四边形 , ∴AB //CD , CD AB =
ODC OEB ∠=∠
又 O 为 BC 的中点, ∴CO BO =
在 BOE ?和 COD ?中 ,,
??
?
??=∠=∠∠=∠CO BO COD BOE ODC OEB ; ∴BOE ?≌ COD ?(AAS ) ∴OE OD =
∴四边形 BECD 是平行四边形 ;
(2) 90 (3) 100
19. 如图 , 某办公楼 AB 的后面有一建筑物 CD, 当光线与地面成 ?22的夹角时 , 办公楼在建筑 物的墙上留下高 1米高的影子 CE; 而当光线与地面成 ?45的夹角时 , 教学楼顶 A 在地面上的 影子 F 与墙角 C 有 20米 的距离 (点 B,F,C 在同一条直线上 ) (1)求办公楼的高度 ;
(2)若要在 AE 之间挂一些彩旗 , 请计算 A , E 之间的距离 .(结果精确到 1m, 参考数据 :
5
222tan , 161522cos , 8322sin ≈?≈?≈
? 解:(1)过点 E 作 AB EM ⊥, 垂足为 M. 设 AB 为 x 米 ,
在 ABF Rt ?中 , ?=∠45ABF
, ∴x AB BF ==米 ,
∴米 )
20(+=+=x CF BF BC , 在 AEM Rt ?中 , 米 )
1(-=-=-=x CE AB BM AB AM , 又 ?=∠=
∠22
, tan
AEM AE
AM
AEM , ∴
201≈+-x x 15≈,
故办公楼 AB 的高度约为 15米 ;
(2)由 (1),得 米 352015=+=+==CF BF BC ME
在 AEM Rt ?中 , AE
ME
AEM =
∠cos ,
∴米 371516
3516
153522cos ≈?≈≈
?
=
ME
AE , 故 AE 的长约为 37米 .
20. 直线 b kx y +=与反比例函数 ) 0(6
>=
x x
y 的图象分别交于点 A (m,3) 和点 B (6, n )
, 与坐标轴分别交于点 C 和点 D. (1)求直线 AB 的解析式。
(2)若点 P 是 x 轴上一动点,当 COD ?和 ADP ?相似时,求点 P 的坐标。
【解答】 解:(1)∵ y=kx+b与反比例函数 y=(x >0)的图象分别交于点 A(m , 3)和点 B (6, n ) , ∴ m=2, n=1,
∴ A (2, 3) , B (6, 1) , 则有
,
解得 ,
∴直线 AB 的解析式为 y=﹣ x+4
(2)如图①当 PA ⊥ OD 时,∵ PA ∥ OC , ∴△ ADP ∽△ CDO , 此时 p (2, 0) .
②当 AP′⊥ CD 时,易知△P′DA∽△ CDO ,
∵ A (2, 3) , B (6, 1) ,直线 AB 的解析式为 y=﹣ x+4, ∴直线 P′A 的解析式为 y=2x﹣ 1,
令 y=0,解得 x=,
∴P′(, 0) ,
综上所述,满足条件的点 P 坐标为(2, 0)或(, 0) .
21.小王是“新星厂”的一名工人,请你阅读下列信息:
信息一:工人工作时间:每天上午 8:00~12:00, 下午 14:00~18:00, 每月工作 25天; 信息二:小王生产甲、乙两种产品的件数与所用时间的关系见下表:
信息三:按件计酬,每生产一件甲产品可得 1.50元,每生产一件乙产品可得 2.80元; 信息四:该厂工人每月收入由底薪和计酬工资两部分构成,小王每月的底薪为 1900元,请 根据以上信息,回答下列问题:
(1)小王每生产一件甲种产品和一件乙种产品分别需要多少分钟?
(2) 2018年 1月工厂要求小王生产甲种产品的件数不少于 60件,则小王该月收入最多是 多少元?此时小王生产的甲、乙两种产品分别是多少件?
【解答】 解:(1)设小王每生产一件甲种产品和一件乙种产品分别需要 x 分钟、 y 分钟,则 由题意得 ,解得 ;
答:小王每生产一件甲种产品和一件乙种产品分别需要 15分钟、 20分钟;
(2)设小王生产甲种产品 a 件(a ≥ 60) ,则生产乙种产品
20
15 -
60
8
25a
?
?
件,总收入为 w 元,根据题意可得:
W=1900+1.5a+2.8×
20
15 -
60
8
25a
?
?
=-0.6a+3580 ∵ -0.6<>
∴ w 随着 a 的增大而减小
∵ a ≥ 60
∴ a=60时, w 有最大值 .
此时 w=-0.6×60+3580=3544(元) . 生产乙种产品 :
20
60
15-60825???=555(件)
答:该月小王收入最多是 3544元,此时生产甲、乙两种产品各为 60件、 555件。
22. 如图,在 Rt △ ABC 中,∠ ACB =90°,∠ A =30°,点 O 为 AB 中点,点 P 为直线 BC 上的动 点(不与点 B 、点 C 重合),连接 OC 、 OP ,将线段 OP 绕点 P 顺时针旋转 60°,得到线段 P Q ,连接 BQ .
(1)如图 1,当点 P 在线段 BC 上时,请直接写出线段 BQ 与 CP 的数量关系.
(2)如图 2,当点 P 在 CB 延长线上时,(1)中结论是否成立?若成立,请加以证明;若 不成立,请说明理由;
(3)如图 3,当点 P 在 BC 延长线上时,若∠ BPO =15°, BP=4,请求出 BQ 的长.
解:(1)结论:BQ=CP.
理由:如图 1中,作 PH ∥ AB 交 CO 于 H .
在 Rt △ ABC 中,∵∠ACB=90°,∠A=30°,点 O 为 AB 中点, ∴ CO=AO=BO,∠CBO=60°, ∴△ CBO 是等边三角形,
∴∠ CHP=∠COB=60°,∠ CPH=∠CBO=60°, ∴∠ CHP=∠CPH=60°, ∴△ CPH 是等边三角形, ∴ PC=PH=CH, ∴ OH=PB,
∵∠ OPB=∠ OPQ+∠ QPB=∠ OCB+∠ COP , ∵∠ OPQ=∠OCP=60°, ∴∠ POH=∠ QPB ,∵ PO=PQ, ∴△ POH ≌△ QPB ,
∴ PH=QB, ∴ PC=BQ.
(2)成立:PC=BQ.
理由:作 PH ∥ AB 交 CO 的延长线于 H .
在 Rt △ ABC 中,∵∠ACB=90°,∠A=30°,点 O 为 AB 中点, ∴ CO=AO=BO,∠CBO=60°, ∴△ CBO 是等边三角形,
∴∠ CHP=∠COB=60°,∠ CPH=∠CBO=60°, ∴∠ CHP=∠CPH=60°, ∴△ CPH 是等边三角形, ∴ PC=PH=CH, ∴ OH=PB,
∵∠POH=60°+∠ CPO ,∠QPO=60°+∠ CPQ , ∴∠ POH=∠ QPB ,∵ PO=PQ, ∴△ POH ≌△ QPB , ∴ PH=QB, ∴ PC=BQ.
(3)如图 3中,作 CE ⊥ OP 于 E ,在 PE 上取一点 F ,使得 FP=FC,连接 CF . ∵∠OPC=15°,∠ OCB=∠ OCP+∠ POC , ∴∠POC=45°,
∴ CE=EO,设 CE=EO=a ,则 FC=FP=2a , EF=a ,
在 Rt △ PCE 中,
a
=
∵ PC+CB=4,
∴(
+
) a +a =4,
解得 a =4﹣ 2,
∴ PC=4
﹣ 4,
由(2)可知 BQ=PC, ∴ BQ=4
﹣ 4.
23.如图,已知抛物线 y=ax2+bx+c过点 A (﹣ 1, 0) , B (3, 0) , C (0, 3) ,点 M 、 N 为抛物 线上的动点,过点 M 作 MD ∥ y 轴,交直线 BC 于点 D ,交 x 轴于点 E .
(1)求二次函数 y=ax2+bx+c的表达式;
(2)过点 N 作 NF ⊥ x 轴,垂足为点 F ,若四边形 MNFE 为正方形(此处限定点 M 在对称轴的 右侧) ,求该正方形的面积;
(3)若∠DMN=90°, MD=MN,求点 M 的坐标.
解:(1)∵抛物线 y=ax2+bx+c过点 A (﹣ 1, 0) , B (3, 0) , C (0, 3)代入 y=ax2+bx+c中 得:a=﹣ 1,
∴所求抛物线解析式为 y=﹣ x 2+2x+3;
(2)由(1)知,抛物线的对称轴为 x=﹣ =1,
如图,设点 M 坐标为(m ,﹣ m 2+2m+3) ,
∴ ME=|﹣ m 2+2m+3|,
∵ M 、 N 关于 x=1对称,且点 M 在对称轴右侧,
∴点 N 的横坐标为 2﹣ m ,
∴ MN=2m﹣ 2,
∵四边形 MNFE 为正方形,
∴ ME=MN,
∴ |﹣ m 2+2m+3|=2m﹣ 2,
分两种情况:
①当﹣ m 2+2m+3=2m﹣ 2时,解得:m 1=、 m 2=﹣ (不符合题意,舍去) ,
当 m=时,正方形的面积为(2﹣ 2) 2=24﹣ 8;
②当﹣ m 2+2m+3=2﹣ 2m 时,解得:m 3=2+, m 4=2﹣ (不符合题意,舍去) , 当 m=2+时,正方形的面积为 [2(2+)﹣ 2]2=24+8;
综上所述,正方形的面积为 24+8或 24﹣ 8.
(3)设 BC 所在直线解析式为 y=kx+b,
把点 B (3, 0) 、 C (0, 3)代入表达式,得:
,解得:,
∴直线 BC 的函数表达式为 y=﹣ x+3,
设点 M 的坐标为(a ,﹣ a 2+2a+3) ,则点 N (2﹣ a ,﹣ a 2+2a+3) ,点 D (a ,﹣ a+3) , ①点 M 在对称轴右侧,即 a >1,
则 |﹣ a+3﹣(﹣ a 2+2a+3) |=a﹣(2﹣ a ) ,即 |a2﹣ 3a|=2a﹣ 2,
若 a 2﹣ 3a ≥ 0,即 a ≤ 0或 a ≥ 3, a 2﹣ 3a=2a﹣ 2,
解得:a=或 a=<1(舍去)>1(舍去)>
若 a 2﹣ 3a <0,即 0≤="" a="" ≤="" 3,="" a="" 2﹣="" 3a="2﹣" 2a="">0,即>
解得:a=﹣ 1(舍去)或 a=2;
②点 M 在对称轴左侧,即 a <>
则 |﹣ a+3﹣(﹣ a 2+2a+3) |=2﹣ a ﹣ a ,即 |a2﹣ 3a|=2﹣ 2a ,
若 a 2﹣ 3a ≥ 0,即 a ≤ 0或 a ≥ 3, a 2﹣ 3a=2﹣ 2a ,
解得:a=﹣ 1或 a=2(舍) ;
若 a 2﹣ 3a <0,即 0≤="" a="" ≤="" 3,="" a="" 2﹣="" 3a="2a﹣">0,即>
解得:a=(舍去)或 a=;
综上,点 M 的横坐标为(, ? 5 2 ? 3
2
17) 、 (2,3)、 (-1,0)、 (, ? 5
2
+3 2
17)
范文二:【参考答案】2018年郑州高三一模生物
2018年高中毕业年级第一次质量预测 生物 参考答案
一、选择题 (本题包括 30个小题,每小题只有一个选项符合题意。每小题 2分,共 60分) 题 号 12345678910答 案 B D C D A B B C A D 题 号 11121314151617181920答 案 C D D C C B C B D C 题 号 21222324252627282930答 案 C A D C B C C D D D
二、非选择题 (除注明的外,每空均为 1分,共 40分)
31. (12分)
(1)气孔 6叶绿体基质 酶 五碳化合物(C 5)
(2)减小 降低 暗反应 非气孔因素
(3) 14丙 甲
32. (11分)
(1)离子(Ca 2+) 抽搐
(2)维生素 D 肾脏、骨骼和小肠(写出两个即可)
(3) (负)反馈调节 使血钙的含量维持在正常的生理范围之内
(4)提高细胞代谢速率,影响神经系统发育和功能 含量最高 提前发育成一只幼蛙 甲 状腺激素含量增高, PTH 的含量就会降低,骨骼中钙的释放减少,从而有利于前肢的发育 (2分)
33. (9分)
(1)样方法 重 营养结构
(2)油松→红脂大小蠹→昆虫甲 三
(3)化学 正己烷(溶液) 受虫害油松 油松遭受虫害后,能产生和释放某种吸引昆虫 甲的化学物质
34. (8分)
(1)两者碱基对的排列顺序不同
(2)不是
(3) ①常染色体 性染色体 遵循 F 1中雄兔由于基因突变产生了 X b 的精子, 并与卵细胞 结合
②白脂肪∶黄脂肪 =4∶ 5(2分)
范文三:2016郑州一模英语答案
郑州201?6年高中毕?业年级模拟?
英语 参考答案
一、选择题(1-60):
1.C 2.A 3.B 4.C 5.B 6.C 7.B 8.C 9.A 10.B 11.C 12.C 13.A 14.A 15.C 16.B 17.A 18.B 19.C 20.B
21.C 22.A 23.D 24.B 25.D 26.A 27.B 28.C 29.D 30.A 31.C 32.C 33.D 34.A 35.B 36.G 37.D 38.E
39.C 40.A 41.B 42.D 43.C 44.A 45.B 46.C 47.A 48.D 49.A 50.C 51.B 52.D 53.D 54.B 55.C 56.A
57.B 58.C 59.D 60.C
二、英语知识运?用第二节(61-70):
61. by 62. a 63. When / As 64. cover?ed 65. what 66. (were) follo?wing 67. to see 68. Sadly? 69. as 70. (have) made
三、短文改错:
Have you ever been to Wuzhe?n? It is so beaut?iful a villa?ge that I had alrea?dy visit?ed it many
have
times?. Locat? in ingJiaxi?ng, Zheji?ang provi?nce, it has a histo?ry of about? 6,000 years?. Like many
Locat?ed
small? towns? in the south?ern area, which? has a lot of small? bridg?es going? throu clean?gh? strea?ms.
it over / acros?s
Local? peopl?e live in old house?s, ? they are very frien?dly. Durin?g the day, you can walk or sit on
and
a boat to enjoy?ing the natur?al scene?ry along? the strea?m. The scene? at night? is attra as well. ?ctive?ly
enjoy? attra?ctive?
There? are all kinds? of round? and squar. Every?e light? time I look at the pictu??res for which? I took, I
light?s
will remem?ber the water?, the bridg?es and the house?s. I love an amazi?ng water? count?ry!
the
(注:第75题,若把the?y改为wh?o亦可;第76题,若删除to?亦可。)
四、书面表达(One possi?ble versi?on):
Notic?e
In order? to encou?rage Senio?r Three? stude?nts to take exerc?ise and relax? thems?elves?, we’re going? to organ?ize a mount?ain-climb?ing activ?ity on April? 10. We’re to gathe?r at the schoo?l gate and start? at 7:20 a.m. by bus and get back at 7:00 p.m. We’ll climb? Mangs?han Mount?ain in the morni?ng, on top of which? we’ll have a picni?c at noon. In the after?noon we’ll be divid?ed into group?s and have a free time. Remem?ber to take photo?s and make notes? for the photo? exhib?ition? or the essay? conte?st to be held later? at our schoo?l. Besid?es, take your lunch? and drink?ing water? with you. If you want to join, pleas?e come to Stude?nt Union? and sign up befor?e April? 5.
Stude?nt Union?
March? 30
评卷细则
一、机器阅卷部?分(共100分?)
1-20题,共20小题?,每小题1.5分,共计30分?(不计入总分?)。
21-40题,共20小题?,每小题2分?,共计40分?。
1
41-60题,共20小题?,每小题1.5分,共计30分?。
二、人工阅卷部?分(共50分)
(一)英语知识运?用第二节
61-70题,共10小题?,每小题1.5分,共计15分?。
1(单词拼写正?确、形式正确,每小题给1?.5分。
2(英、美拼写及词?汇用法均可?接受。
(若只写出单?词的原形,但形式不正?确,不给分(若字母的大?、小写出错,视为错误)。 3
4(若书写较差?以致影响评?判,不给分。
5(若不在指定?答题位置答?题,不给分。
6(若用铅笔答?题,不给分。
(二)短文改错
本题共10?小题,每小题1分?,共计10分?。
1(每找准一处?错误,改错符号正?确、答案正确、且答案写在?指定的位置?,给1分,不能出现给?半分的现象?。只允许修改?10处错误?,多者(从第11处?起)不计分。若字母的大?、小写出错,视为错误。
2(若找准错误?,改错符号正?确,但答案不正?确,不给分。
3(每处错误及?其修改均仅?限一词,若与此不符?,不给分。
4(若找准错误?,答案正确,但改错符号?不正确,或没有改错?符号,或答案未写?在指定的位?置,不给分。
5(若一处错误?用两种改错?符号,不给分。
(用文字表述?答案,或不用指定?符号改错,不给分。 6
7(凡与该题参?考答案不符?者,不给分。
8(若用铅笔答?题,不给分。
注意:
1(给分前,先确定考生?改正的错误?个数。若多于10?处,只评前10?处,从第11处?起,无论考生答?对与否,均不给分。
2(若考生未找?够10个错?误,按其改正的?正确处的个?数给分。
3(若考生改错?的顺序与答?案不一致,但改错的数?量在10个?以内,按其改正的?正确处的个?数给分。
(三)书面表达
1(评分原则
(1)本题总分为?25分,按5个档次?给分。
(2)评分时,首先根据文?章的内容和?语言初步确?定其所属档?次,然后以该档?次的要求来?衡量,确定或调整?档次,最后给分。
(3)词数少于8?0和多于1?20的,从总分中减?去2分。
(4)评分时,应注意的主?要内容为:内容要点、应用词汇和?语法结构的?数量和准确?性、上下文的连?贯性及语言?的得体性。
(5)拼写与标点?符号是语言?准确性的一?个方面,评分时,应视其对交?际的影响程?度予以考虑?。英、美拼写及词?汇用法均可?接受。
(6)如果书写较?差,以致影响交?际,将分数降低?一个档次。
(7)如果时态出?错较多,从得分中扣?除3-5分。
(8)用铅笔答题?,不给分。
2(各档次的给?分范围和要?求
(1)第五档:21—25分。
2
完全达到了?试题规定的?任务,完全达到了?预期的写作?目的。 ?覆盖所有内?容要点。
?应用了较多?的语法结构?和词汇。
?语法结构或?词汇方面有?些许错误,但为尽力使?用较复杂的?结构或较高?级词汇所致?。
?具备较强的?语言应用能?力。
?有效地使用?了语句间的?连接成分,使全文结构?紧凑。 2)第四档:16—20分。 (
完全达到了?试题规定的?任务,达到了预期?的写作目的?。 ?虽漏掉1、2个次重点?,但覆盖所有?主要内容。
?应用的语法?结构和词汇?能满足任务?的要求。
?语法结构或?词汇方面应?用基本准确?,些许错误主?要是因尝试?较复杂的语?法结构或词?
汇所致。
?应用简单的?语句间的连?接成分,使全文结构?紧凑。 (3)第三档:11—15分。
基本完成了?试题规定的?任务,整体而言,基本达到了?预期的写作?目的。 ?虽漏掉一些?内容,但覆盖所有?主要内容。
?应用的语法?结构和词汇?能满足任务?的要求。
?有一些语法?结构或词汇?方面的错误?,但不影响理?解。 ?应用简单的?语句间的连?接成分,使全文内容?连贯。 (4)第二档:6—10分。
信息未能清?楚地传达给?读者。 未恰当完成?试题规定的?任务,
?漏掉或未描?述清楚一些?主要内容,写了一些无?关的内容。 ?语法结构单?调、词汇项目有?限。
?有一些语法?结构方面的?错误,影响对写作?内容的理解?。 ?较少使用语?句间的连接?成分,内容缺少连?贯性。
(5)第一档:1—5分。
未完成试题?规定的任务?,信息未能传?达给读者。
?明显遗漏主?要内容,写了一些无?关内容,原因可能是?未理解试题?要求。 ?语法结构单?调、词汇项目有?限。
?有较多语法?结构或词汇?方面的错误?,影响对写作?内容的理解?。 ?缺乏语句间?的连接成分?,内容不连贯?。
(6)0分
未能传达给?读者任何信?息:内容太少,无法评判;写的内容均?与所要求的?内容无关或?
所写内容无?法看清。
3
范文四:2018河南省郑州市九年级一模英语试卷(答案+最详尽解析)
2017-2018河南省郑州市九年级一模英语试卷(答案 +最详尽解析)
一.听力(略)
二、单项选择 (15小题每小题 1分 , 共 15分 ) 从 A 、 B 、 C 、 D 四个选项中选出可以填入空白 处的最佳选项并在答题卡上将该项涂黑。
21. With____ development of science and technology, China has entered ____ new era (时代 ) . A. a; an B. a; the C. the; a D. the; /
22. Being good at reading_____on people?s faces helps Bob get on well with his workmates. A. attention B. expressions C. suggestions D. direction
23. --Have you got all your textbooks?
--Don't worry, mom._____ is left. They are all in my school.
A. Each B. Nothing C. Neither D. None
24. The housing price in my hometown has increased by two percent ______ the past two months. A. During B. till C. at D. on
25. Very little in the house_____ after the big fire was put out.
A. missed B. appeared C. rose D. remained
26. This is a five-star hotel, so you are not allowed to enter if you don?t dress______.
A. Poorly B. comfortably C. badly D. properly
27. I felt the cook lied because he _______to avoid meeting my eyes.
A. Is trying B. was trying C. has tried D. will try
28. Be yourself! Never follow anyone else's path(道路) ______you're in the woods and you are lost.
A. unless B although C. while D. if
29. HUAWEI Mate 10 is very hot and it was______ in a few minutes on the first day of the sale. A. cleaned out B. handed out C. sold out D. found out
30.Jane is very popular in our class because she has a kind and _____personality.
A. outgoing B. silent C. mean D. doubtful
31. Nowadays, high-speed trains, Alipay, shared bicycles and online shopping ______ the New Four great Inventions in China.
A, was called B. are called C. are calling D. have called
32. Although looking after kids ______sound like a simple job, great care is still needed.
A. May B. must C. shall D. should
33. When life gives you a hundred reasons to cry, life that you have a thousand reasons to smile. A. Showing B. to show C. showed D. show
34. Lucy is a girl______ loves to steal the show and be the center of the attention.
A. What B. who C. which D. whose
35. Which of the following is correct?
A. ?The Old Man and the Sea》 is my favorite book.
B. Before we got to the cinema. The movie had started.
C. No one knew why he was absent from school yesterday.
D. The teacher said: Bringing mobile phones to school isn?t allowed.
三、完形填空(10小题,每小题 1分,共 10分)
先通读短文,掌握其大意,然后从 A 、 B 、 C 、 D 四个选项中选出一个可以填入相应空白处 的最佳选项,并在答题卡上将该项涂黑。
As a child, I truly feared the dark. I was also afraid of getting lost and not being liked by others. These fears were very real and caused me some __36__ moments.
Maybe sometimes the things in my room looked and sounded strange, which made me feel frightened. My mother always kept a small nightlight on for me. There was __37__ total darkness inside, but a street light or passing car lights made clothes hanging over a chair become the shape __38__ a wild animal. Out of the corner of my window, I saw the curtains(窗帘) seem to move when there was no __39__. A tiny sound would seem a hundred times __40__ than in the daytime. My heart would beat fast. All I could do was to __41__ still (静止的) in bed so that the “enemy”would not discover me.
Another of my childhood fears was that I would get lost, especially on my way home from school. Every morning I __42___ the school bus right near my home. That was no problem. After school, all the buses were lined up along the street, but I was afraid that I would get on the __43__ one and be taken to some other strange places. On school trips to a park, I wouldn?t let the leaders out of my sight.
One of the processes(过程) of growing up is being able to __44__ our fears. It can help us to deal with our lives when we grow up __45__ we understand the things that scared us when we were children.
36. A. happy B. dangerous C. relaxing D. uncomfortable 37. A. sometimes B. usually C. always D. never
38. A. like B. in C. for D. against 39. A. sunlight B. rain C. wind D. snow
40. A. lower B. louder C. heavier D. lighter 41. A. hide B. lay C. spread D. lie
42. A. got off B. got on C. got in D. got up 43. A. fast B. slow C. wrong D. direct 44. A. overcome B. refuse C. support D. avoid
45. A. though B. if C. until D. before 四、阅读理解 (20小题每小题 2分 , 共 40分 )
阅读下面四篇语言材料,然后按文后要求做题。
A
Are too many kids obsessed (着迷 ) with texting?
根据材料内容选出最佳选项 , 并在答题卡上将该项涂黑。
46. Who doesn?t think many kids are obsessed with texting?
A. Riley B. Tom C. Ella D.Shanna
47. What does Riley think of kids? texting on the phone?
A. They should stop texting too much and talk more.
B. They have the ability to control themselves in texting.
C. Spending time outdoors is better than texting.
D. Spending much time on a screen is not healthy for brain. 48. Which of the following is TRUE according to the text?
A. It's common to see kids texting everywhere.
B. Kids spend more time exercising than texting.
C. All kids are responsible and know when to stop texting.
D. Kids shouldn't have time alone on their phone to talk with friends. 49. Theunderlinedword
A. sometimes B. all the time C. seldom D. from time to time 50. What kind of text is it?
A. A speech. B. A story C.A notice D. A survey
B
US President Donakd Trump showed the video of his 5-year-old granddaughter, Arabella, singing and reciting poems in Chinese to President Xi Jinping when he paid his first visit to China. It became a hot topic.
What the video didn 't show is the growing movement by many American
families to have their children study Chinese at a young age.
“It was a surprise for everyone to see the little girl speak Chinese excellently, and it? s such a wonderful honor to their parents, ” said Corman, founder and president of a private language school in Manhattan where Ivanka Trump? s three children studied Chinese.
She said the school has seen a major increase in American families having their
children learn Chinese. And now there are more than 100 at the school.
She said the families learning Chinese at the school are from all over the world, and they are there for different reasons. There are families where one or both parents are from China, who want their children to keep their traditional culture, there are American families who are interested in China and it? s culture.
“Americans have completely changed their plans about learning foreign languages,
and we even have their children start learning foreign languages as young as four months,” added Corman.
Besides Ivanka Trump, many wealthy parents are also pushing their young children to learn Chinese, including Amazon founder Jeff Bezos and his wife Mackenzie, and Facebook CEO Mark Zuckerberg and his wife, Priscilla Chan.
根据内容选出最佳选项 , 并在答题卡上将该项涂黑。
51. What was the hot topic during Trump's first visit to China?
A.Arabella ? s Chinese show. B. Trump? s wealth.
C.Corman's language D. Ivanka? s three children.
52. More Americans choose to learn Chinese for the following reasons EXCEPT that_______. A. China has a large market.
B. they are interested in China and its culture.
C.they are bored with other foreign languages.
D.Chinese-Americans want to keep Chinese traditional culture.
53. What can we learn about Corman in the text?
A. She visited China with Trump. B. She is good at teaching Chinese.
C. She manages a language school. D. Her children are learning Chinese.
54. Why does the writer mention famous persons like Zuckerberg in the text?
A. To make an ad for Corman's language school,
B. To give examples of how famous people like China.
C. To encourage children of wealthy families to learn Chinese.
D.To show more Americans pay attention to Chinese leaning at early age.
55.What's the beat title of the text?
A. Trump?s first visit to China B. Chinese fever in the US.
C. The early learning of Chinese.D. The interest of American families.
C
High-tech machines have made life easier for millions around the word. However, some people still prefer low-tech ways of doing things. Here's an example of why this is happening. You can microwave a frozen hamburger in 60 seconds. However, it won't taste as good as one you cook on the stove(炉 ). And if you're in that much of a hurry, you probably won?t take time to toast (烘烤 )the bread. High-tech cooking saves time, but it doesn't make better tasting meals.
Most people get their news from high-tech sources(来源 ) like television or the Internet. This has many advantages. For example, electronic news is more up to date than newspapers or magazines. It's also more exciting to see live and videotaped news events than photographs. However, newspapers and magazines have some important advantages. They give more background and details(细节 ). They also let you read the parts that are important to you and skip the rest. Other high-tech timesavers have similar disadvantages. For example, most people use the phone or email to stay in touch with friends and family members who live in other places. But when you use the Internet or the phone, you don't always think carefully about what you are saying, and sometimes you forget the important things you want to communicate. Similarly, when you do your homework on the computer, you needn't check your spelling by yourself. However, you are so busy with the computer that you don 't pay enough attention to the actual words they are writing.
根据材料内容选出最佳选项 , 并在答题卡上将该项涂黑。
56. What advantages of high-tech machines does the writer mention in the text?
A. They made more delicious meals.
B. They can save time and make life easier.
C. They can provide news with detailed information.
D. They can make students do their homework carefully.
57. How many advantages does the news from high-tech sources have according to the text? A. Two B. Three C. Four D. Five
58. Which of the following is NOT true according to the text?
A. We sometimes forget important things to say when talking on the phone.
B. We won?t miss important information while reading newspapers and magazines.
C. We can get the latest news from high-tech sources like television or the Internet.
D. When we email our friends, we are always careful to choose the right words to say.
59. What is the writer?s attitude towards high-tech machines?
A. The writer thinks high-tech machines are perfect
B. The writer shows no interest in high-tech things.
C. The writers expresses that each coin has two sides.
D. The writer expects people to use more high-tech things.
60. In which section of a magazine may the text appear?
A. News B. Music and art.
C. Sports D. Science and technology.
D
If you want to learn a new language, the very first thing to think about is why. ___61____ Or perhaps you're interested in the books, films or music of a different country and you know how much it will help to have a good knowledge of the language.
Most people learn best in their own ways, but traditional classes are an ideal(理想的 )start for many people. ___62___ It truly takes time to learn a language. You will have more success if you study more often, so try to develop a routine(例行程序 ).___63___
Many people may think they're so old that they give up learning a language. Yes, children do learn languages more quickly than adults, but some research has shown that you can learn a language at any age. ____64___
Learning a new language is never easy. ____65___And you'll be amazed by the praise of some people when you say just a few words in their own language. Good luck!
根据材料内容 , 从下面五个选项中选出能填入文中空缺处的最佳选项使短文意思通顺、 内 容完整 , 并在答题卡上将该项涂黑
五、词语运用(10小题,每小题 1分,共 10分)
阅读短文, 从方框中选择适当的词并用其正确形式填空, 使短文通顺、 意思完整。 请将答案 填写在答题卡相应的位置上。每空限填一词,每词限用一次。方框中有两个词是多余的。
Young people are often unhappy when they are with their parents. They say their parents don?t understand them. They often think their parents are too strict with them.
Parents often find it difficult to win their __66__ trust and they seem to forget how they themselves felt when they were young. For example, young people like to do things __67__ much thinking. It?s one of their ways to show that they have grown up and they can solve any difficult problems. Older people worry more __68__. Most of them plan things ahead and don?t like their plans to be __69__.
So when you want your parents to let you do something, you will be __70__ if you communicate enough with them before you really start doing it.
Young people often make their parents __71__ by the clothes they wear, the music they enjoy and something else. __72__ they don?t mean to cause any trouble. They just feel that in this way they can be cut off from the old people?s world and they want to make a new culture of their own. And if young people are not satisfied with their parents, they just stay at home alone instead of __73__ out with their parents.
If you plan to control your life, you?d better __74__ to get them to understand you. If your parents see that you have a high __75__ of responsibility, they will certainly give you the right to do what you want to do.
六、 补全对话 (5小题 , 根据下面的对话白处填上一个适当的句子 , 使对话的意思连贯、 完整。 A: Hi, Nick! Are these pictures of you when you were a kid in English?
B: Yeah. 76._______________________.
A: Ah! But now you are really tall. People sure change.
B: Sometimes greatly. By the way, guess what? I just got invited to our Chinese teacher's house for dinner. What gift am I supposed to take? What I am not so good at Chinese customs.
A :77.__________________________.
B: Good idea! I have another problem. My Chinese hasn't improved a lot since I came here in China. 78. __________________________?
A: You need to talk more just like what we are doing
B: Okay. Time to go. I am taking the bus there. 79. ___________________________?
A: The nearest bus stop? Don't worry. I will drive you to her home.
B: Many thanks.
A: 80.________________________________.
七 . 书面表达(15分)
生活中有许多美好事情值得回忆。你的美好回忆是什么 ? 它是怎么发生的 ? 请以 “My sweet memory
注意 :文中不得出现真实的姓名和校名
My sweet memory
范文五:2018年河南省郑州九年级一模模拟测试数学试题及答案
郑州2015年九年级一模模拟测试
数学试题
一选择题(每小题3分,共24分,下列各小题均有四个答案,其
中只有一个是正确)
1.,5的绝对值是 ( )
11,5,A. B. C. D. 5 55
2.下列四个交通标志中,轴对称图形是( )
x,,20,3.不等式组: 的解集在数轴上表示正确的是( ) ,11,,x,
4.某校有21名学生参加某比赛,预赛成绩各不同,要取前11名参加决赛,小颖已经知道了自己的成绩,她想知道自己能否进入决赛,只需要再知道这21名同学成绩的( ) A(最高分 B。平均分 C.极差 D.中位数
5.一个几何体的三视图如图所示,则这个几何体摆放的位置是
主视图 左视图 ( )
俯视图
C
26.三角形两边的长是3和4,第三边的长是方程的xx,,,12350根,
则该三角形的周长为( )
A. 14 B. 12 C. 14 或12 D.以上都不对 7.如图,线段AB是?O的直径,弦CD?AB,?CAB =20?, 则?AOD等于( )
A. 160? B. 150?
C. 140? D(120?
8.如图,在正方形ABCD中,AB=3cm,动点M自A点出发沿AB方向以每秒1cm的速度运动,同时动点N从A点出发沿折线AD?DC?CB以每秒,cm的速度运动,到达B时运动同时停止,设
2?AMN的面积为y(cm),运动时间为x(秒),则下列图象中能大致反映y与x之间的函数关系的是
(
)
二、填空题(每小题3分,共21分)
09.计算:=______________ 9(21),,
10.一副三角板叠在一起如图放置,最小锐角的顶点D恰好放在
等腰直角三角板的斜边AB上,BC与DE交于点M,如果?ADF
,100?,那么?BMD为_____________度
4y,11.如图,A、B两点在双曲线上,分别经过A、B两点向坐x
标轴作垂线,已知S=1,则__________________ SS,,阴影12
12.如图,经过点B(,2,0)的直线与直线相ykxb,,yx,,42交于点A(,1,,2),则不等式4x+2<><0的解集为__________________>0的解集为__________________>
13.三辆车按1,2,3编号,舟舟和嘉嘉两人可任意选坐一辆车,则两人同坐3号车的概率是______
14.如图,在Rt?ABC中,?ABC=90?,AB=3,AC=5,点E在BC上,将?ABC沿AE折叠,使点B落在AC边上的点B′处,则BE的长为___________
15.如图,正方形ABCD的边长为3cm,E为CD边上一点,?
A A C DAE=30?,M为AE的中点,过点M作直线分别与AD、BC相交
M B′ 于点P、Q,若PQ=AE,则AP等于___________cm. E
B C E 第14题 B C 第15题
三、解答题(本题共8个小题,共75分)
2xxx,,,369116.(8分)请你化简 ,再取恰当x的值代,,22xxxx,,,,1211
入求值。
17.(9分)为了解中考体育科目训练情况,某县从全县九年级学生中随机抽取了部分学生进行了一次中考体育科目测试(把测试结果分为四个等级:A级:优秀;B级良好;C级及格;D级不及格),并将测试结果绘制成了如下两幅不完整的统计图。请根据统计图中的信息解答下列问题。
体育测试各等级学生 人数扇形图
B级30%
C级35% , A级 D级
图1
图2 (,)本次抽样测试的学生人数是,,,,(
,(,)图1中?的度数是______,并把图2条形统计图补充完整;
(3)该县九年级学生3500名,如果全部参加这次中考体育科目测试,请你估计不及格的人数为__________ (4)测试老师想4位同学(分别记为E、F、G、H,其中E为小明)中随机选择两位同学了解平时训练情况,请用列表或树形图的方法求出选中小明的概率
18.(9分)放风筝是大家喜爱的一
种运动,星期天的上午小明在大洲广
场上放风筝。如图他在A处时不小心
让风筝挂在了一棵树的树梢上,风筝
, 固定在了D处,此时风筝线AD与水平线的
B D 夹角为30?,为了便于观察。小明迅速向
A 前边移动边收线到达了离A处7米的B处,
C , O 此时风筝线BD与水平线的夹角为45?。已
第19题, 知点A、B、C在同一条直线 上,?ACD=90?,
请你求出小明此时所收回的风筝线的长度是多少米,(本题中
31.732,21.414,风筝线均为线段,。最后结果精确到1米)
119.(10分)如图,已知A(,4,)B(,1,2)是一次函数2
mym,,(0)ykxb,,与反比例函数图象的两个交点,AC?x轴于C,x
BD?y轴于D;
(1)根据图象直接回答:在第二象限内,当x取何值时,一次
函数大于反比例函数的值,
(2)求一次函数解析式及m的值;
(3)P是线段AB上的一点,连接PC,PD,若?PCA和?PDB面积相等,求点P的坐标。
A D
N 20.(9分)如图,在正方形ABCD中,点P M是BC边上的任一点,连接AM并将线段
AM绕M顺时针旋转90?得到线段MN,在B M C CD边上取点P使CP,BM,连接NP,BP。
(,)求证:四边形BMNP是平行四边形;
(2)线段MN与CD交于点Q,连接AQ,若?MCQ??AMQ,则MB与CM存在怎样的数量关系, 请说明理由。
21.(9分)某商场试销一种成本为每件60元的服装,规定试销期间销售单价不低于成本单价,且获利不得高于45%,经试销发现,销售量y(件)与销售单价x(元)符合一次函数,y=kxb,且x=65时,y=55;x=75时,y=45;
(1)求一次函数的解析式;
(2)若该商场获得利润为w元,试写出利润w与销售单价x之间的关系式;销售单价定为多少时,商场可获得最大利润,最
大利润是多少元,
(3)若该商场获得不低于500元,试确定销售单价x的范围;
22.(10分)阅读: Rt?ABC和Rt?DBE,AB=BC,DB=EB,D在AB上,连接AE,AC,如图
??AEB??CDB(SAS) 1 求证:AE,CD,AE?CD。
?AE,CD,?EAB,?DCB
??DCB+?CDB,90?,?ADK=?CDB 证明: 延长CD交
??ADK+?DAK=90?
??AKD=90??AE?CD。 AE于,
在?AEB和?CDB中
0,,,,,ABECBD90
,? ABBC,,
,BEDB,,
(2)类比: 若关系和位置关系还成立吗,若成立,请给予证明;若不成立,请说明理由。将(1)中的Rt?DBE绕点B逆时针旋转一个锐角,如图2所示,问(1)中线段AE,CD之间数量;
(3)拓展: 在图2中,将“AB=BC,DB=EB”改为“AB=kBC,DB=kEB,k>1”其它条件均不变,如图3所示,问(1)中线段AE,CD间的数量关系和位置关系还成立吗,若成立,请给与证明;若不成立,请说明理由。
A A
A
K D D K K D O O
E B C B C B C
图1 E 图2 E 图3
223(11分)如图,抛物线与x轴交A、B两点(A点yxx,,,23
l在B点左侧),直线与抛物线交于A、C两点,其中C点的横坐标为2.
(1)求A、B两点的坐标及直线AC的函数表达式; (2)P是线段AC上的一个动点,过P点作,轴的平行线交抛物线于E点,求线段PE长度的最大值;
(3)点G是抛物线上的动点,在x轴上是否存在点F,使A、C、F、G这样的四个点为顶点的四边形是平行四边形,如果存在,y
求出所有满足条件的F点坐标;如果不存在,请说明理由。
A O B x
P
C
E
九年级数学试卷 评分人
一、 选择题(每题3分,共24分) 复评人
1._______________2.______________3._____________4.________
5.___________6.____________7.____________ 8.________
评分人
复评人 二、填空题(21分)
9._______________10._______________11.___________12. ____________
13._______________14.________________15.______________
三解答题
2xxx,,,3691评分人 ,,16. (8分)请你化简 ,再取22xxxx,,,,1211复评人
恰当x的值代入求值。
17.
(,)本次抽样测试的学生人数是,体育测试各等级学生
,,,( 人数扇形图
,的度数是______,(,)图1中?
并把图2条形统计图补充完整;
B级30% (3)该县九年级学生3500名,如果
全部参加这次中考体育科目测试,请C级35% , 你估计不及格的人数为__________ A级 (4)测试老师想4位同学(分别记为D级
E、F、G、H,其中E为小明)中随机
选择两位同学了解平时训练情况,请图1 用列表或树形图的方法求出选中小
18 (9分)
19. (9分) ,
B D
A
C , O
第19题,
20. (9分) A D
N P
B M C
(9分) 21题
22题(10分) A A
A
K D D K K D O O E B C B C B C
图1 E 图2 E 图3
23题(11分)
y
A O B x
P
C
E
2015年郑州市九年级模拟
(数学)(答案) 一、选择题(每题3分,共24分)
题号 1 2 3 4 5 6 7 8 答案 D C B D A B C B 二、填空题(每题3分,共21分)
题号 9 10 11 12 13 14 15
13 2答案 4 85 6 1或 ,,,,21x 92三、解答题(本大题8分,共75分) 16.原式
=
=
=
=
=,
2?x,1?0,x+3?0,x,1?0,x+1?0, ?取x=2,
代入得:原式==(
1217. 解:(1)本次抽样测试的学生人数是:(人), ,4030%故答案为:40;
6(2)根据题意得:360?×=54?, 40
C级的人数是:40,6,12,8=14(人),
如图:
(3)根据题意得:
83500×=700(人), 40
(4)根据题意画树形图如下:
共有12种情况,选中小明的有6种,
61则P(选中小明)==( 212
18. 解:设CD为x米(
??ACD=90?,
3x?在直角?ADC中,?DAC=30?,AC=CD?tan30?=,
2x在直角?BCD中,?DBC=45?,BC=CD=x,BD= 37xx,,
32又??1.414,?1.732,
?x=10米,
2x则小明此时所收回的风筝的长度为:AD-BD=2x- 所以x=6米
19.
20. 证明:在正方形ABCD中,AB=BC,?ABC=?B,
在?ABM和?BCP中,
ABBC,,,, ,,,ABCB,,CPBM,,
??ABM??BCP(SAS),
?AM=BP,?BAM=?CBP,
??BAM+?AMB=90?,
??CBP+?AMB=90?,
?AM?BP,
?AM并将线段AM绕M顺时针旋转90?得到线段MN,
?AM?MN,且AM=MN,
?MN?BP,
?四边形BMNP是平行四边形;
(2)解:BM=MC(
理由如下:??BAM+?AMB=90?,?AMB+?CMQ=90?,
??BAM=?CMQ,
又??B=?C=90?,
??ABM??MCQ,
AMAB?=, MQMC
??MCQ??AMQ,
??AMQ??ABM,
ABAM?, ,BMMQ
ABAB?, ,MCBM
?BM=MC(
6555kb,,,,kb,,,1120,,21. 根据题意得解得( 7545.kb,,,
yx,,,120所求一次函数的表达式为(
22Wxxxxx,,,,,,,,,,,,,(60)(120)1807200(90)900?, ?抛物线的开口向下,
xx,90W60??x87?当时,随的增大而增大,而,
2x,87W,,,,,(8790)900891?当时,(
87?当销售单价定为元时,商场可获得最大利润,最大利润是
891元(
2W,5005001807200,,,,xx?由,得,
2xx,,70110,xx,,,1807700012整理得,,解得,(
由图象可知,要使该商场获得利润不低于500元,销售单价应
x6087??x在70元到110元之间,而,所以,销售单价的范围是
7087??x(
22. 解析:(2)AE=CD,AE?CD, ??DBE=?ABC=90?,
??ABE=?DBC,
在?AEB和?CDB中,
??AEB??CDB,
?AE=CD,?EAB=?DCB,
??DCB+?COB=90?,?AOK=?COB, ??KOA+?AOK=90?,
??AKC=90?,
?AE?CD;
1(3)AE=CD,AE?CD, k
?BC=kAB,DB=kEB,
ABBE1?==, BCBDk
BEBD?, ,ABBC
??DBE=?ABC=90?,
??ABE=?DBC,
??AEB??CDB,
AEAB1?,?EAB=?DCB, ,,CDBCk
1?AE=CD, k
?k,1,
?AE?CD,
??DCB+?COB=90?,?AOK=?COB,
??KAO+?AOK=90?,
??AKC=90?,
?AE?CD(
23. 解:(1)令y=0, 解得x=,1或x=3, 12
?A(,1,0),B(3,0), 将C点的横坐标x=2,
2代入y=x,2x,3,
得:y=,3,
?C(2,,3);
?直线AC的函数解析式是: y=,x,1;
(2)设P点的横坐标为x(,1?x?2),
则P、E的坐标分别为: P(x,,x,1),
2E(x,x,2x,3),
?P点在E点的上方,
2PE=(,x,1),(x,2x,3)
2219=,x+x+2=,(x,)+, 24
19?当时,PE的最大值=; x,42
(3)存在4个这样的点F,分别是: F(1,0),F(,3,0),F(4+,0),F(4,,0)( 1234
?如图1,
连接C与抛物线和y轴的交点, 那么CG?x轴,此时AF=CG=2, 因此F点的坐标是(,3,0); ?如图2,
AF=CG=2,
A点的坐标为(,1,0),
因此F点的坐标为(1,0);
?如图3,
此时C,G两点的纵坐标关于x轴对称, 因此G点的纵坐标为3,代入抛物线中, 即可得出G点的坐标为(1?,3), 由于直线GF的斜率与直线AC的相同, 因此可设直线GF的解析式为:
y=,x+h,
将G点代入后,
可得出直线的解析式为:
y=,x+7(
因此直线GF与x轴的交点F的坐标为: (4+,0);
?如图4,
同?可求出F的坐标为:(4,,0); 综合四种情况可得出,存在4个符合条件的F点(
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