sat经典数学题汇总

《sat经典数学题汇总》由会员上传分享，免费在线阅读，更多相关内容在应用文档-天天文库。

1、SAT经典数学题汇总SAT经典数学题汇总Inthelinesegmentpicturedbelow,AB+CD=AD,andAB=BC.IfAD=15,whatisthedistancebetweenthemidpointsofADandBC? Note:Figuremaynotbedrawntoscale.(A)0.5(B)1.5(C)3(D)4.5(D)7.52.Whichofthefollowinglinesisperpendiculartoy=3x+4andhas6foritsx-intercept?(A)y=3x–6(B)y=–3x+6(C)y=–x+6

2、(D)y=–x–2 (D)y=–x+2 3.Whichofthefollowinginequalitiesisgraphedbelow? (A)y>–2x–2(B)y≥–2x–2(C)y<–2x–2(D)y>x–2 (D)y>–x–2 4.Thefollowingequationrepresentswhichtypeofgraph?2y=–6x2+24x–12(A)Aparabolathatopensdownwardwithvertex(–2,6)(B)Aparabolathatopensupwardwithvertex(6,2)(C)Aparabolathatop

3、ensupwardwithvertex(–2,–6)(D)Aparabolathatopensdownwardwithvertex(2,6)(D)Aparabolathatopensdownwardwithvertex(–6,2)Explanations1.BIfyouunderstandhowtoanswerthisquestion,youshouldbeabletoansweranyquestiondealingwithlinesegmentsontheMathIC.Thequestionasksyoutofindthedistancebetweentwomid

4、points,soyoufirstneedtofindwherethosemidpointsare.Bydefinition,amidpointisapointequidistantfrombothendsofalinesegment.SothemidpointofADis152=7.5unitsfromeitherend.TofindthemidpointofBC,youfirstneedtofindthelengthofBC.Fromthefigure,youcanseethatBC=AD–AB–CD.SinceitisgiventhatAB+CD=2 5AD,

5、ThemidpointofBCis92=4.5unitsfromBandC.ButinordertomeasurethedistancebetweenthemidpointsofBCandAD,youmustsituatethemidpointofBCwithregardtoAD.YoucandothisbyfindingoutthemidpointofBC’sdistancefrompointA.Therefore,themidpointofBCis4.5+4.5=9unitsfroma,whereasthemidpointofADis7.5unitsfroma.

6、Thedistancebetweenthesetwomidpointsis9–7.5=1.5.2.ETheslopeofy=3x+4is3.Alineperpendiculartothislinehasaslopethatistheoppositeofthereciprocalof3,or–13.Ifthex-interceptofthedesiredlineis6,thenthelinecontainsthepoint(6,0),andwehaveenoughinformationtoputitinpoint-slopeform:(y–0)=–13(x–6).Th

7、issimplifiestoy=–13x+2.3.ATheslopeofthelinepicturedis–126=–2.They-interceptofthelinepicturedis–2.Sotheequationofthelinepicturedisy=–2x–2.Thisleavesthreechoices.Thelineinthepictureisdotted;thismeansthattheinequalityiseither,not≤or≥.Nowwehavetwochoicesleft.Becausetheregiontotherigh