数学参考答案及评分细则第1页（共19页）2025届高中毕业班适应性练习卷数学参考答案及评分细则评分说明：1．本解答给出了一种或几种解法供参考，如果考生的解法与本解答不同，可根据试题的主要考查内容比照评分标准制定相应的评分细则。2．对计算题，当考生的解答在某一步出现错误时，如果后继部分的解答未改变该题的内容和难度，可视影响的程度决定后继部分的给分，但不得超过该部分正确解答应给分数的一半；如果后继部分的解答有较严重的错误，就不再给分。3．解答右端所注分数，表示考生正确做到这一步应得的累加分数。4．只给整数分数。选择题和填空题不给中间分。一、选择题：本题考查基础知识和基本技能。每小题5分，满分40分。1．C2．D3．A4．A5．B6．C7．A8．B二、选择题：本题考查基础知识和基本技能。每小题6分，满分18分。全部选对的得6分，部分选对的得部分分，有选错的得0分。9．AD10．ABD11．ACD三、填空题：本题考查基础知识和基本技能。每小题5分，满分15分。12．24yx=13．()2gxx=（写出一个满足条件的函数即可）14．116四、解答题：本题考查基础知识、基本技能、基本思想和基本经验，考查发现问题、提出问题、分析问题和解决问题的能力。共5小题，满分77分。15.本小题主要考查数列的基本概念、等比数列等基础知识，考查运算求解能力、逻辑推理能力等，考查函数与方程思想、分类与整合思想等，考查数学运算、逻辑推理等核心素养，体现基础性和综合性．满分13分．解法一：（1）因为11nnaS+−=，所以当2n时，11nnaS−−=，··················································1分所以110nnnnaaSS+−−−+=，························································································2分所以122nnaan+=（）．·································································································4分当1n=时，2112aS=+=，满足212aa=，也符合12nnaa+=．·············································5分因为10a≠，所以0na≠，12nnaa+=，所以{}na是以1为首项，2为公比的等比数列，································································6分所以12nna−=．··········································································································7分数学参考答案及评分细则第2页（共19页）（2）由（1）知12nna−=，所以212nnnb−=，·······································································8分所以221221(1)(1)222nnnnnbnnbn+−++==．······················································································9分令11nnbb+>，解得2121n−+<<+，··········································································10分因为*n∈N，所以1n=或2n=．所以当1n=或2n=时，11nnbb+>，又因为0nb>，所以1nnbb+>；·······································11分同理，当3n且*n∈N时，1nnbb+<．··········································································12分所以nb的最大值为394b=．·...