【文档说明】黑龙江省哈尔滨市第三中学2022-2023学年高三上学期第二次验收考试 数学 答案.pdf,共(5)页,268.204 KB,由envi的店铺上传
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1哈三中2022—2023学年度上学期高三学年第二次验收考试数学答案123456789101112ABCDCBADADBCCDCD13.()1,314.1−15.37,37−16.4317.(1)()1
62sin2+−+=mxxf,+−+kkkx,,222262,解得单调递增区间为+−kkk,,63.(2)当−,6x时,−+613662,x,162sin2−=+mx有
三个不等实根,则111m−−,,02m,.18.(1)()1121naan−=+++−,()()1122nnnan−=+检验11a=符合,则()112nnna−=+(2)()211211nbnnnn==−++,则1111122122311nnSnnn=−
+−++−=++19.(1)①23SABAC=,12sin3cos2bcAbcA=,sin3cosAA=,tan3A=,0,2A,3A=②22cos1cos22BCA+=
+,22sin1cos22AA=+,21cos12cos1AA−=+−,22coscos10AA+−=,()1coscos12AA==−舍,0,2A,3A=2③3sincoscaCcA
=−,sin3sinsinsincosCACCA=−,sin0C,1sin62A−=,,0,2A,3A=(2)2sinsinsinabcABC===,2sin,2sinbBcC==,2sin2sinbcBC+=+,23BC+=,23CB=−,22sin
2sin23sin36bcBBB+=+−=+,,62B,(3,23bc+,(33,33abc+++20.(1)()211232623S=−=−,2tanOF=,2122432432tanta
nS=−=−,12232436,tan,3tan3SSS=+=+−−(2)设236,tan,3tan3y=+,()()222223sin13sin126sin26sinsinsiny+−−=−==,13
sin,,023y,33sin,,032y,32sin,tan32==即时,y取最小值,此时S取最大值.21.(1)1232+−=nnnaS,1232111+−=+++nnnaS,作差得nnnnaaa233211−−=++,nnn
aa231+=+,)2(3211nnnnaa+=+++,而1=n时,32,1,12321111=+=+−=aaaS,数列nna2+是等比数列,nnnnnnaa23,32−==+.(2)nnnnnanb3)12()2)(12(−=+−=,利用倍差法分别求得33)1(1+
−=+nnnM.(3)1223+−=nnnnncca,11232−−−=nnnnc,111111111322132223322232−−−−−−−−−=−+=−=nnnnnnnnnnnc323)321(2332132121−=−
−nnnT22.(1)()00f=,()()()ln1ln11xxxxfxexxexeax=++++++,故()0fa=,则函数()fx在()()0,0f处的切线方程为yax=;(2
)当0a=时,()()ln1xgxxexm=+−,则()()()()()()21ln111xxxgxexxexhxx=+++=++则有()()()2ln11xhxxx=+++,则()()23201xxhxx++
=+对1x−恒成立则有()hx为()1,−+上的单调递增函数,又由()00h=知,x()1,0−0()0,+()gx−0+()gx单调递减极小值单调递增又由于当1x→−时,()fx→+,且当x→+时,()fx→+故函数()g
x有两个零点,只需m的取值范围为()0,+(3)首先:设()()()ln1xfxFxexax==++,则有:()()()ln11xxxeFxexehxx=++=+,即()()1ln11hxxx=+++则有:()()()20,01xhxxx=+,即()hx为(
)0,+上的单调递增函数,4则有:当()0,x+时,()()010hxh=,即()0Fx对任意()0,x+恒成立,则()Fx为()0,+上的单调递增函数,对任意的()12,0,xx+,由于1210xxx+,知()()121FxxFx+,即()()()11212
1xfxxxxfx++............①同理()()()212122xfxxxxfx++............②由①②可得:()()()1212fxxfxfx++.获得更多资源请扫码加入享学资源网微信公众号www.xiangxue100.com