2012武汉中考数学压轴题 下载本文

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Pushing ahead, East, North, West development, facilitating shanty, complete xincheng West Road, stability and reconstruction of the street, Star Ding garden built century Garden District, subject public housing construction, heating the gas expansion accelerated implementation, Jing Rui River and bridge style line solid shaft, further expanded the town development. Beautiful country adhere to the advance and typical for a group to lead. According to \ogical lay based, and industry increased income, and live upgrade civilization, and culture rich connotation\ht, caught built beautiful village, and whole village dvance, and easily relocation, and \d three built\oject near 30 a; depth into ecological, and industry, and culture, and tourism, elements, high standards caught party original city Liu, and jade are Xia AO, model village, in province City set has benchmark. Four is equal benefits to promote sharing, coordinated development of various social undertakings. In the case of rigid spending slowing revenue growth, increase, financial 75% to the people's livelihood, the masses have more access in the sharing. Cuoban something good and benefit. Adhere to the affordable, best, carefully cuoban village oil, water and heat, cultural, city and County columns practical, developments benefit families, bring more welfare to the masses. Development of social convenience. Acceptance of balanced development of compulsory education through the national assessment, the County vocational education center was named \onal education in China\batch of national reform and development model through provincial ... Five is to deepen reform and innovation to break bottlenecks and endogenous development of effective fire. As an engine of dynamism, adding reform key to adopting reform measures stress energy and break bottlenecks and promoting development. Pay close attention to the key areas of reform. Conscientiously implement the provincial deployment and cancel, adjustment, to undertake the administrative approval items according to Regulation 347 to further improve administrative efficiency continuing deepening reform for poverty alleviation, speeding up rural land right registration certification pilot project, encouraging the orderly transfer of land management, utilize the land resources, in order to promote scale management laid the Foundation. Actively cultivate the market. Firmly establish a market-oriented, nurturing family farms, industrial users, professional cooperation organization new market management main body 456, effectively improve the industry, intensive and marketization of encouraging support social capital into the small micro-credit, urban development, culture and tourism, public services and other areas, easing development shortfall. To promote mass innovation. o support the rural sector to use new thinking and new ideas, creative work incentives such as actively promoting financial intermediation, bring added 159 in non public enterprises, individually-1540, created a2012武汉中考数学压轴题

12.已知,直角梯形ABCD中,AB∥CD,∠D=900,AB=AC,AE⊥AC,AE=AD,点M在BC上且BM=MC,连BE交AC于F,则下列结论:

(1)BF=EF (2)MF⊥BC (3)BD=2MF(4)4S△BFM=S△ABD 其中正确的结论有: A、(1)(2) B、(1)(3) C、(1)(2)(3) D、(1)(3)(4)

16.如图,P.Q为双曲线y=

k上的两点,过x两点分别作x轴y轴的垂线,垂足为A.B 连OP .PQ如果S四OPQB=11,且OB=3OA, 则K=

22.如图:AB为⊙O的直径,C为⊙O上一点,AD和过C点的切线互相垂直,垂足为D, (1)求证AC平分∠DAB

(2)设AD交⊙O于E,若AE=2,DC=3 求⊙O的半径

23用长度一定的不锈钢材料设计成外观为矩形的框架(如图○1○2○3中的一种).设竖档AB=x米,请根据以上图案回答下列问题:(题中的不锈钢材料总长度均指各图中所有黑线的长度和,所有横档和竖档分别与AD、AB平行)

(1)在图○1中,如果不锈钢材料总长度为12米,当x为多少时,矩形框架ABCD的面积为3平方米?

(2)在图○2中,如果不锈钢材料总长度为12米,当x为多少时,矩形框架ABCD的面积S最大?最大面积是多少?(

(3)在图○3中,如果不锈钢材料总长度为a米,共有n条竖档,那么当x为多少时,矩形框架ABCD的面积S最大?最大面积是多少?

Pushing ahead, East, North, West development, facilitating shanty, complete xincheng West Road, stability and reconstruction of the street, Star Ding garden built century Garden District, subject public housing construction, heating the gas expansion accelerated implementation, Jing Rui River and bridge style line solid shaft, further expanded the town development. Beautiful country adhere to the advance and typical for a group to lead. According to \ogical lay based, and industry increased income, and live upgrade civilization, and culture rich connotation\ht, caught built beautiful village, and whole village advance, and easily relocation, and \d three built\oject near 30 a; depth into ecological, and industry, and culture, and tourism, elements, high standards caught party original city Liu, and jade are Xia AO, model village, in province City set has benchmark. Four is equal benefits to promote sharing, coordinated development of various social undertakings. In the case of rigid spending slowing revenue growth, increase, financial 75% to the people's livelihood, the masses have more access in the sharing. Cuoban something good and benefit. Adhere to the affordable, best, carefully cuoban village oil, water and heat, cultural, city and County columns practical, developments benefit families, bring more welfare to the masses. Development of social convenience. Acceptance of balanced development of compulsory education through the national assessment, the County vocational education center was named \onal education in China\batch of national reform and development model through provincial ... Five is to deepen reform and innovation to break bottlenecks and endogenous development of effective fire. As an engine of dynamism, adding reform key to adopting reform measures stress energy and break bottlenecks and promoting development. Pay close attention to the key areas of reform. Conscientiously implement the provincial deployment and cancel, adjustment, to undertake the administrative approval items according to Regulation 347 to further improve administrative efficiency continuing deepening reform for poverty alleviation, speeding up rural land right registration certification pilot project, encouraging the orderly transfer of land management, utilize the land resources, in order to promote scale management laid the Foundation. Actively cultivate the market. Firmly establish a market-oriented, nurturing family farms, industrial users, professional cooperation organization new market management main body 456, effectively improve the industry, intensive and marketization of encouraging support social capital into the small micro-credit, urban development, culture and tourism, public services and other areas, easing development shortfall. To promote mass innovation. o support the rural sector to use new thinking and new ideas, creative work incentives such as actively promoting financial intermediation, bring added 159 in non public enterprises, individually-1540, created a

○1 ○2 ○3

(第23题图)

【答案】12题B

16.K=-6

22题(1)略 (2)R=2

23解: (1)当不锈钢材料总长度为12米,共有3条竖档时, 12-3x

BC==4-x,

3∴x(4-x)=3. 解得,x=1或3.

12-4x

(2)当不锈钢材料总长度为12米,共有4条竖档时,BC=,矩形框架ABCD的面

312-4x4

积S=x·=-x2+4x.

3343

当x=-=时,S=3.

422×(-)

3

3

∴当x=时时,矩形框架ABCD的面积S最大,最大面积为3平方米.

2

a-nx

(3)当不锈钢材料总长度为a米,共有n条竖档时,BC=,矩形框架ABCD的面积

3a-nxnaS=x·=-x2+x.

333

a

3

aa2=时,S= 2n12n

当x=-

n2×(-)

3

aa2

∴当x=时,矩形框架ABCD的面积S最大,最大面积为平方米

2n12n

24.如图E为正方形ABCD的边BC上任一点,将△ABE逆

时针旋转90到△ADF的位置。延长ED与AF的延长线交于G

(1)当E为BC中点时,求

DG的值 DEPushing ahead, East, North, West development, facilitating shanty, complete xincheng West Road, stability and reconstruction of the street, Star Ding garden built century Garden District, subject public housing construction, heating the gas expansion accelerated implementation, Jing Rui River and bridge style line solid shaft, further expanded the town development. Beautiful country adhere to the advance and typical for a group to lead. According to \ogical lay based, and industry increased income, and live upgrade civilization, and culture rich connotation\ht, caught built beautiful village, and whole village advance, and easily relocation, and \d three built\oject near 30 a; depth into ecological, and industry, and culture, and tourism, elements, high standards caught party original city Liu, and jade are Xia AO, model village, in province City set has benchmark. Four is equal benefits to promote sharing, coordinated development of various social undertakings. In the case of rigid spending slowing revenue growth, increase, financial 75% to the people's livelihood, the masses have more access in the sharing. Cuoban something good and benefit. Adhere to the affordable, best, carefully cuoban village oil, water and heat, cultural, city and County columns practical, developments benefit families, bring more welfare to the masses. Development of social convenience. Acceptance of balanced development of compulsory education through the national assessment, the County vocational education center was named \onal education in China\batch of national reform and development model through provincial ... Five is to deepen reform and innovation to break bottlenecks and endogenous development of effective fire. As an engine of dynamism, adding reform key to adopting reform measures stress energy and break bottlenecks and promoting development. Pay close attention to the key areas of reform. Conscientiously implement the provincial deployment and cancel, adjustment, to undertake the administrative approval items according to Regulation 347 to further improve administrative efficiency continuing deepening reform for poverty alleviation, speeding up rural land right registration certification pilot project, encouraging the orderly transfer of land management, utilize the land resources, in order to promote scale management laid the Foundation. Actively cultivate the market. Firmly establish a market-oriented, nurturing family farms, industrial users, professional cooperation organization new market management main body 456, effectively improve the industry, intensive and marketization of encouraging support social capital into the small micro-credit, urban development, culture and tourism, public services and other areas, easing development shortfall. To promote mass innovation. o support the rural sector to use new thinking and new ideas, creative work incentives such as actively promoting financial intermediation, bring added 159 in non public enterprises, individually-1540, created a(2)当DG=DA时,作∠GDC的平分线反向延长交AF于N,连BN。 求证:BN-DN=2AN

证明:(1)过E作EH//FG交CF于H 则

DGDF? DEDH1 2 tan∠1= tan∠2=

∵可设CH为a,则CE=2a=BE=DF ∴DC=4a DH=3a ∴

DG2? DE3(2)作DK⊥AG,BM⊥直线AG于M ∴∠6=∠3=∠5

∴∠6+∠7=∠10=∠9=∠5+∠11 ∴∠11=∠7=450 ∴DN=2NK

易证△BAM≌△ADK(AAS) ∴BM=AK AM=DK=KN ∴AM+AN=NK+AK ∴MN=AK=BM ∴BN=2MN

∴BN-DN=2(MN-KN)=2(AK -KN)=2AN

25.(本题12分)如图1,Rt?ABC中,?ACB?90?,AC?BC,点A、C在x轴上,线段AB与y轴正半轴相交于点D,开口向上的抛物线y=a(x-1)2 经过点B、D.已知OC=3.

(1)求抛物线的解析式;