湖南省长沙市2025届高三八月开学六校联合检测试题(数学)

湖南省长沙市2025届高三八月开学六校联合检测试题(数学)试卷答案,我们目前收集并整理关于湖南省长沙市2025届高三八月开学六校联合检测试题(数学)得系列试题及其答案,更多试题答案请关注本网站↓↓↓

试题答案

湖南省长沙市2025届高三八月开学六校联合检测试题(数学)试卷答案

以下是该试卷的部分内容或者是答案亦或者啥也没有,更多试题答案请捕获只因

B2Hstheers'sdi共)用则庆育香A.Heisangrywiththem.代暗三C,Heisdoubfulaboutthem..数个四d.D,Heisnterestedinthem.面B.Heiscarefulaboutthem.小os共)-第3.Howmanybenefitsofavegetariandietarementionedinparagraph3?1(12TC.5,odD.6.34.WhydoestheauthormentionDaveScottinparagraph5?A.Toshowwhatavegetariandietis.bB.Tosuggestavegetariandietishealthy.C.Topresentastudyonvegetariandiets1D.Toexplorewhysomeathletesarevegetarians..d35.Whatis.theibesttitleforsthetext?)A.MyroadtobeingavegetarianB.NeverregretyourownchoiceC.BeingavegetarianismychoiceD,Misunderstandingsaboutvegetariandiets第二节(共5小题;每小题2分,满分10分)991bluo2I,j29d0mmob9d2idbisls日.9wB9m(漏根据短文内容,从短文后的选项中选出能填入空白处的最佳选项

选项中有两项为多余选项

nidd11.191o.viixns.oi2o1q9bFeedyourmindI2IsotodnoisWehaveknownaboutthelinkbetweenwhatweeatandourphysicalhealthforalongtime.36TheMentalHealthFoundationproducedareportcalled"FeedingMinds".Thereportstatesthatthebrainisaphysicalpartofourbodythatneedsthecorrectfoodtoworkproperly,justliketheheart.Thisfoodshouldcontaincarbohydrates(a碳水化合物),vitaminsandfishoil.o99n81q9Thereisalsoresearchthatshowshowagooddietcanimprovethebehaviorofchildrenandtheirconcentration.DanielBrownistheheadteacherofBarnetSchool.I37b9191u09.,1Withregardtolseriousmentabillnesses,JackaandSanchezVillegassaythateatingfruit,vegetablesandfishhelpstopreventdepression.38SomeresearchlalsorevealsthatahealthydietcanpreventAlzheimer's(aseriousmentalhealthproblemfortheelderly).However,manymedicalprofessionallsfeelthattheresearchbyJackaandSanchez-Villegasistooearly.o39DrJohnPowell,apsychologist(心a理学家),thinksthatalthoughmanyofhispatientswithdepressionhaveapoordiet,thatisprobablynotthereasonfortheirillness.Theresearchrecommendsthatpeopleeafparticularfoodforparticularmentalhealthissues.Toimproveyourmemory,eatsalmonandnuts.Toimproveyourconcentration,eatvegetables.40Ifdepressionisaproblem,eatbrownrice.w)nwobbomls.nwobsod.A.0aOverall,itseemsclearthatweneedtoeathealthyfoodforourmind.Althoughwedonotfullyunderstandthelinkbetweenthetwo,wesuggestthatwechoosethisasanimportanttopicforpublicity.A.Westillneedtotesttheirclaims.B.Ifyouhaveproblemssleeping,eatnuts.gainidr.C.Isyourusualdiethealthyforbothyourmindandbody?11.D.Buteatingalotofsugarmakesdepressionmorelikely.E.TryeatingagoodbreakfastbecausethatgivesyoualotofenergyforthedayF.Recently,wehavelearnedmoreaboutthelinkbetweenourdietandourmind.G.Hesaysafterhisschoolstoppedsellingjunkfood,thestudents'concentrationlevelsincreased.2023高考桂柳鸿图综合模拟金卷(3)英语第6页(共8页)

分析(1)由f(x)是定义域为R的奇函数,从而可以得到$\left\{\begin{array}{l}{f(0)=0}\\{f(-1)=-f(1)}\end{array}\right.$,带入解析式便可解出a=2,b=1;
(2)先分离常数得到$f(x)=-\frac{1}{2}+\frac{1}{{2}^{x}+1}$,可根据单调性的定义判断该函数的单调性,
(3)根据函数奇偶性和单调性的关系将不等式进行转化求解即可.

解答解:(1)f(x)是定义在R上的奇函数;
∴f(0)=0,且f(-1)=-f(1);
∴$\left\{\begin{array}{l}{\frac{-1+b}{2+a}=0}\\{\frac{-\frac{1}{2}+b}{1+a}=-\frac{-2+b}{4+a}}\end{array}\right.$;
解得b=1,a=2;
即$f(x)=\frac{1-{2}^{x}}{{2}^{x+1}+2}$;
(2)f(x)在R上单调递减.
$f(x)=\frac{1-{2}^{x}}{{2}^{x+1}+2}=\frac{-({2}^{x}+1)+2}{2({2}^{x}+1)}$=$-\frac{1}{2}+\frac{1}{{2}^{x}+1}$;
设x1,x2∈R,且x1<x2,则:
$f({x}_{1})-f({x}_{2})=\frac{1}{{2}^{{x}_{1}}+1}-\frac{1}{{2}^{{x}_{2}}+1}$=$\frac{{2}^{{x}_{2}}-{2}^{{x}_{1}}}{({2}^{{x}_{1}}+1)({2}^{{x}_{2}}+1)}$;
∵x1<x2
∴${2}^{{x}_{1}}<{2}^{{x}_{2}}$;
∴${2}^{{x}_{2}}-{2}^{{x}_{1}}>0$;
又${2}^{{x}_{1}}+1>0,{2}^{{x}_{2}}+1>0$;
∴f(x1)>f(x2);
∴f(x)在R上单调递减.
(3)若对任意的t∈(1,4),不等式$f(4-k\sqrt{t})+f(t)>0$恒成立,
即f(t)>-f(4-k$\sqrt{t}$),
∵函数f(x)是奇函数,
∴f(t)>-f(4-k$\sqrt{t}$)=f(k$\sqrt{t}$-4),
∵函数f(x)为减函数,
∴t<k$\sqrt{t}$-4,
即k$\sqrt{t}$>4+t,
则k>$\frac{4+t}{\sqrt{t}}$=$\frac{4}{\sqrt{t}}$+$\sqrt{t}$,
∵t∈(1,4),∴$\sqrt{t}$∈(1,2),
设x=$\sqrt{t}$,
则x∈(1,2),
则g(x)=x+$\frac{4}{x}$在(1,2)上为减函数,
则g(2)<g(x)<g(1),
即4<g(x)<5,即k≥5.

点评本题主要考查函数奇偶性的应用以及函数单调性的判断,利用参数分离法结合函数单调性的性质是解决本题的关键.