河北省2023-2024学年度第一学期九年级完美测评④数学.考卷答案

河北省2023-2024学年度第一学期九年级完美测评④数学.考卷答案试卷答案,我们目前收集并整理关于河北省2023-2024学年度第一学期九年级完美测评④数学.考卷答案得系列试题及其答案,更多试题答案请关注微信公众号:考不凡/直接访问www.kaobufan.com(考不凡)

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河北省2023-2024学年度第一学期九年级完美测评④数学.考卷答案试卷答案

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9.HowoldisDavidnow?A.35.B.15.10.What'stheprobablereltiohipbeweehespeakers?C.20.A.Classmates.d鸿听第8段材料,回答第11至13题

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C.Herfatheraskedherto.修改

13.Whatwillthespeakersdonext?A.Gototheman'shome.B.Readonlinetogether.听第9段材料,回答第14至16题

C.Gotobuysomenovels.14.Whatdoesthemanwanttodo?A.GototheHydeParkHotel.B.GoonashorttourofLondon.readiC.Gosightseeingwiththewoman.and15.Whichisadestinationofthemanonthesecondday?A.TheTowerofLondon.B.TheHydePark.asty16.Whichisthesuitabletimeforthemantoarriveforthetrip?C.WestminsterAbbeyA.5:30p.m.B.6:30a.m.C.7:30a.m.听第10段材料,回答第17至20题

17.WhatdoesthespeakerthinkofthefoodinWaltDisneyWorld?A.Unpleasant.B.Attractive.C.Mostpopular.e18.Wherearethesteaksintherestaurantfrom?A.Florida.B.Orlando.C.SouthDakota.19.WhocanswiminthepooloftheonlyAAAFiveDiamondresort?修A.Adults.B.Children.C.Babies.20.Whatcanpeopledoat8p.m.sharp?A.Enjoybeautifulfireworks.B.Makesomefoodforthekidinthekitchen.C.Driveashortdistancetoenjoythesoundingviews.第二部分阅读理解(共两节,满分40分)】第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C和D四个选项中,选出最佳选项TheBestSci-fiBooksof2022Wetakealookatthemostexcitingnewsci-fibooksof2022,aswellasthebestsciencefictionnovelsofalltime.TheSaintsofSalvationByPeterF.HamiltonTheOlyixhavelaidsiege()toEarth,harvestingpeoplefortheirgod.Citiesarefallingtotheirdevastatingweaponsandmillionshaveeitherfledtoseekrefugeinspaceorarefightingawarthatseemsunwinable.AsEarth'sdefeatdrawsevercloser,ateamaresenttoinfilrate()theOlyix'sair-ship.Theirplan?Thisisthefinalsei-finovelinPeterF.Hamilton'sextremelysurprisingseriesTheSalvationSequence.【2023年分科诊断测试卷(三)·英语第2页(共8页)】

分析(1)由2x-$\frac{π}{3}$=kπ,k∈Z求出x的值,可得函数图象的对称中心坐标;
(2)先将函数y=sin2x+acos2x利用辅角公式化简,然后根据正弦函数在对称轴上取最值可得答案;

解答解:(1)由2x-$\frac{π}{3}$=kπ,k∈Z得:
x=$\frac{π}{6}$+$\frac{1}{2}$kπ,k∈Z,
故函数y=2sin(2x-$\frac{π}{3}$)的图象的对称中心为($\frac{π}{6}$+$\frac{1}{2}$kπ,0),k∈Z,
(2)由题意知
y=sin2x+acos2x=$\sqrt{{a}^{2}+1}$sin(2x+φ),
当x=$\frac{π}{8}$时函数y=sin2x+acos2x取到最值±$\sqrt{{a}^{2}+1}$,
将x=$\frac{π}{8}$代入可得:sin(2×$\frac{π}{8}$)+acos(2×$\frac{π}{8}$)=$\frac{\sqrt{2}}{2}$(a+1)=±$\sqrt{{a}^{2}+1}$,
解得a=1.

点评本题主要考查三角函数的辅角公式和正弦函数的对称性问题,难度中档.