第六天答案.pdf-2021-02-27-17-11-26-672.pdfVIP免费

第六天1.【答案】A.【解析】01limln1001lim11xxxxxeex，A正确，B错误.1limln111lim1xxxxxeex,C错.1limln111lim1xxxxxeex,D错误.2.【答案】2e【解析】12111100002coslnln11limlimlimlimcotlncot2sinsinsin01lim=1xxxxxxxxxxxxxxxxxxxxeeeeex等价替换3.【答案】3e【解析】22222222000cosln13tan3tanlimlimlimcotln13tancot32sinsin0==(13tan)limxxxxxxxxxxxxeeeex等价替换4.【答案】1e【解析】22244444sin2lntantan1tan11limtan2lntanlimlimlim1tanlim1tancos2cos21tan1tantan2x14limtan=xxxxxxxxxxxxxxxxxxxeeeeee5.【答案】13()abc【解析】000011131lim1limlnlimlimlnlnln333330=()lim3xxxxxxxxxxxxxxxxabcabcabcxxxaabbccxxxxxabceeeeabc洛必达6.【答案】e【解析】111limlimln+lim=xxxxxexexxxexxxeeee洛必达7.【答案】13e【解析】22223200001111arctan1arctanarctan11+lim1limlnlimlim330arctanlim=xxxxxxxxxxxxxxxxxxeeeeex洛必达8.【答案】C【解析】22222lim1limlnlimlimlim()()xxxxxxaxbabxabxxxxxxxaxbxaxbxaxbxaxbabxxeeeeexaxb9.【答案】1e【解析】ln1ln2111ln11lnln11limlimlimln1111lnlimln11lnlnlim(1)=xxxxxxxxxxxexxxxxexxxxxxxeeeee洛必达等价替换10.【答案】12e【解析】22201lncoslncoslimln(1)ln(1)ln(1)00lim(cos)=limxxxxxxxxxee而2200lncosln(1cos1)limlimln(1)ln(1)xxxxxx20cos1limxxx(等价无穷小替换ln(1)xx)220112lim2xxx(等价无穷小替换211cos2xx)故原式=.121ee