上海八年級(jí)數(shù)學(xué)第二學(xué)期數(shù)學(xué)講義4

1、專業(yè)好文檔八年級(jí)數(shù)學(xué)第二學(xué)期數(shù)學(xué)講義4一、填空題：（本大題共12題，每題2分， 滿分24分）1若函數(shù)是一次函數(shù)，則的取值范圍為 2已知一次函數(shù)的圖像經(jīng)過(guò)點(diǎn)，并與直線平行，那么這個(gè)一次函數(shù)解析式是 _3如果一次函數(shù)中y隨x的增大而減小，那么這個(gè)一次函數(shù)一定不經(jīng)過(guò)第_ 象限4在圖中，將直線oa向上平移3個(gè)單位，所得直線的函數(shù)解析式為 第4題圖5方程的解是 _ _第10題圖6方程組的解為 7十二邊形的內(nèi)角和為_(kāi)度8用換元法解方程.如果設(shè)，則原方程可化為y的整式方程是 9已知一個(gè)多邊形的每個(gè)外角都為，那么這個(gè)多邊形是 邊形10如圖，abcd的周長(zhǎng)是28cm，ac和bd交于o，oab的周長(zhǎng)比obc的周長(zhǎng)

2、小2cm，則ab = ，bc = .11解方程組時(shí)，可先化為 和 兩個(gè)方程組12如果直線與兩坐標(biāo)軸所圍成的三角形面積是9，則k的值為 二、選擇題（本大題共6題，每題2分， 滿分12分）13已知函數(shù)，若當(dāng)時(shí)，；當(dāng)時(shí)，a和b的大小關(guān)系是 （ ）（a）ab； （b）a=b； （c）ab； （d）不能確定14下列方程中，是二項(xiàng)方程的為（ ）（a）； （b）； （c）； （d）15下列方程中, 有實(shí)數(shù)解的是（ ）（a）； （b）； （c）； （d） 16 某災(zāi)區(qū)恢復(fù)生產(chǎn)，計(jì)劃在一定時(shí)間內(nèi)種60畝蔬菜，實(shí)際播種時(shí)每天比原計(jì)劃多種3畝，因此提前一天完成任務(wù)，問(wèn)實(shí)際種了幾天？現(xiàn)設(shè)實(shí)際種了x天，則可列方程（ ）

3、（a）； （b）； （c）； （d）17已知平行四邊形的一條邊長(zhǎng)為14，下列各組數(shù)中，能分別作它的兩條對(duì)角線長(zhǎng)的是（ ）（a）10與16； （b）12與16； （c）20與22； （d）10與1818一個(gè)面積為2的平行四邊形被直線分成面積為x，y的兩部分，則y與x之間的函數(shù)關(guān)系只可能是（ ）三、簡(jiǎn)答題（本大題共5題，每題6分， 滿分30分）19解關(guān)于x的方程： 20解方程： 解： 解：21解方程組： 22解方程組： 解： 解：四、解答題（本大題共3題，每題8分， 滿分24分）23如圖，已知a（4，a），b（-2，-4）是一次函數(shù)ykxb的圖象和反比例函數(shù)y的圖象的交點(diǎn)（1）求反比例函數(shù)和一次函

4、數(shù)的解祈式；（2）求a0b的面積解： 24某區(qū)需修建一條2400米長(zhǎng)的封閉式污水處理管道為了盡量減少施工對(duì)市民生活等的影響，實(shí)際施工比原計(jì)劃每天多修10米，結(jié)果提前20天完成了任務(wù)試問(wèn)實(shí)際每天修多少米？解： xoyaefb（第25題圖）25.（本題滿分8分，第（4）小題為附加題，具體評(píng)分標(biāo)準(zhǔn)見(jiàn)參考答案）已知一次函數(shù)的圖像與坐標(biāo)軸交于、點(diǎn)（如圖），平分，交軸于點(diǎn). （1）求點(diǎn)的坐標(biāo)；（2）求直線的表達(dá)式；(3) 過(guò)點(diǎn)作，垂足為，聯(lián)結(jié)of，試判斷ofb的形狀，并求ofb的面積.五、（本大題滿分10分，第（1）小題2分，第（2）小題各4分）26如圖已知一次函數(shù)y=x+7與正比例函數(shù)y=的圖象交于點(diǎn)a

5、，且與x軸交于點(diǎn)b（1）求點(diǎn)a和點(diǎn)b的坐標(biāo)；（2）過(guò)點(diǎn)a作acy軸于點(diǎn)c，過(guò)點(diǎn)b作直線ly軸動(dòng)點(diǎn)p從點(diǎn)o出發(fā)，以每秒1個(gè)單位長(zhǎng)的速度，沿oca的路線向點(diǎn)a運(yùn)動(dòng)；同時(shí)直線l從點(diǎn)b出發(fā)，以相同速度向左平移，在平移過(guò)程中，直線l交x軸于點(diǎn)r，交線段ba或線段ao于點(diǎn)q當(dāng)點(diǎn)p到達(dá)點(diǎn)a時(shí)，點(diǎn)p和直線l都停止運(yùn)動(dòng)在運(yùn)動(dòng)過(guò)程中，設(shè)動(dòng)點(diǎn)p運(yùn)動(dòng)的時(shí)間為t秒當(dāng)t為何值時(shí)，以a、p、r為頂點(diǎn)的三角形的面積為8？是否存在以a、p、q為頂點(diǎn)的三角形是qa=qp的等腰三角形？若存在，求t的值；若不存在，請(qǐng)說(shuō)明理由解：19已知一次函數(shù)的圖像平行于直線，且經(jīng)過(guò)點(diǎn)（2，-3）.（1）求這個(gè)一次函數(shù)的解析式；（2）當(dāng)=6時(shí)，求的

6、值.20已知一次函數(shù)圖像經(jīng)過(guò)點(diǎn)a（-2，-2）、b（0，-4）.(1) 求、的值；（2）求這個(gè)一次函數(shù)與兩坐標(biāo)軸所圍成的面積.21若直線分別交軸、軸于a、c兩點(diǎn)，點(diǎn)p是該直線上在第一象限內(nèi)的一點(diǎn)，pb軸，b為垂足，且sabc= 6.（1）求點(diǎn)b和p的坐標(biāo) .（2）過(guò)點(diǎn)b畫出直線bqap，交軸于點(diǎn)q，并直接寫出點(diǎn)q的坐標(biāo).22某人因需要經(jīng)常去復(fù)印資料，甲復(fù)印社按a4紙每10頁(yè)2元計(jì)費(fèi)，乙復(fù)印社則按a4紙每10頁(yè)1元計(jì)費(fèi)，但需按月付一定數(shù)額的承包費(fèi). 兩復(fù)印社每月收費(fèi)情況如圖所示，根據(jù)圖中提供的信息解答下列問(wèn)題：（1）乙復(fù)印社要求客戶每月支付的承包費(fèi)是 元.（2）當(dāng)每月復(fù)印 頁(yè)時(shí)，兩復(fù)印社實(shí)際收費(fèi)

7、相同.（3）如果每月復(fù)印頁(yè)在250頁(yè)左右時(shí)，應(yīng)選擇哪一個(gè)復(fù)印社?請(qǐng)簡(jiǎn)單說(shuō)明理由.23小杰與小麗分別從相距27千米的a、b兩地同時(shí)出發(fā)相向而行，3小時(shí)后相遇.相遇后兩人按原來(lái)的速度繼續(xù)前進(jìn)， 小杰到達(dá)b地比小麗到達(dá)a地早 1小時(shí)21分.求兩人的行進(jìn)速度分別是多少？24.某街道因路面經(jīng)常嚴(yán)重積水,需改建排水系統(tǒng),市政公司準(zhǔn)備安排甲乙兩工程隊(duì)承接這項(xiàng)工程.據(jù)評(píng)估,如果甲乙兩隊(duì)合作施工,12天可完成;如果甲隊(duì)先做10天,剩下的由乙隊(duì)單獨(dú)承擔(dān),還需15天才能完成.問(wèn):甲乙兩隊(duì)單獨(dú)完成此項(xiàng)工程各需多少天?winger tuivasa-sheck, who scored two tries in the k

8、iwis 20-18 semi-final win over england, has been passed fit after a lower-leg injury, while slater has been named at full-back but is still recovering from a knee injury aggravated against usa.both sides boast 100% records heading into the encounter but australia have not conceded a try since josh c

9、harnleys effort in their first pool match against england on the opening day.aussie winger jarryd hayne is the competitions top try scorer with nine, closely followed by tuivasa-sheck with eight.but it is recently named rugby league international federation player of the year sonny bill williams who

10、 has attracted the most interest in the tournament so far.the kiwi - with a tournament high 17 offloads - has the chance of becoming the first player to win the world cup in both rugby league and rugby union after triumphing with the all blacks in 2011.id give every award back in a heartbeat just to

11、 get across the line this weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskforce, is in london for the football associations 150th anniversary celebrations and will attend citys premier league match at chelsea on sunday.i am going

12、to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.mi

13、chel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said they were surprised and disappointed by toures complaint. in a statement the russian side added: we found no racist insults from fans of cska. baumgartner the

14、 disappointing news: mission aborted.the supersonic descent could happen as early as sunda.the weather plays an important role in this mission. starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon, wit

15、h capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilome

16、ters) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the balloon will slowly drift to the edge of space at 120,000 feet ( then, i would assume, he will slowly step out onto something resembling an olympic diving platform.they blew

17、 it in 2008 when they got caught cold in the final and they will not make the same mistake against the kiwis in manchester.five years ago they cruised through to the final and so far history has repeated itself here - the last try they conceded was scored by englands josh charnley in the opening gam

18、e of the tournament.that could be classed as a weakness, a team under-cooked - but i have been impressed by the kangaroos focus in their games since then.they have been concentrating on the sort of stuff that wins you tough, even contests - strong defence, especially on their own goal-line, completing sets and a good kick-chase. theyve been great at all the unglamorous stuff that often goes unnoticed in the stands