湛江一中2018-2019学年第一学期"第2次大考"
高一级数学科试卷答案
一、单选题(共12题,每题只有一个正确选项,每题5分,共60分)
题号 1 2 3 4 5 6 7 8 9 10 11 12 答案 B B D A B C D C A D D B 二、填空题(共4题,每题5分,共20分)
13.-2 14.②④ 15 . (-∞,-1) 16.
三、解答题(写出详细的解答过程,共6题,第17题10分,其余每题12分,共70分)
17.(10分)解:(1)原式"=1+" "4" /"9" "×" "9" /"4" "+(" √("2" ) "-1)=" √("2" ) "+1" ;························(5分)
(2)原式=1/2 〖log〗_3 27+(lg25+lg4)-2=3/2+2-2=3/2. ·······(10分)
18.(12分)解:(1)不等式 1/4≤2^(x-1)≤128, 即为2^(-2)≤2^(x-1)≤2^7,·····(1分)
所以-2≤x-1≤7,解得-1≤x≤8,所以A={x|-1≤x≤8}.···········(3分)
因为对数函数y=〖"log" 〗_2 x 在["1" /"8" ",32" ]上单调递增,······························(4分)
所以〖log〗_2 1/8≤〖log〗_2 x≤〖log〗_2 32,即-3≤〖log〗_2 x≤5,所以B={y|-3≤"y" ≤"5" }.·····(6分)
(2)由(1)得A∩B={x"|" -1≤x≤5}.···································(7分)
①当C=∅ 时,满足C⊆(A∩B),此时m+1>2m-1,解得m<2.············(9分)
② 当C≠∅ 时,由C⊆(A∩B)得{█(m+1≤2m-1@m+1≥-1@2m-1≤5)┤ ,解得2≤m≤3,··········(11分)
综上m≤3.所以实数m的取值范围是(-∞,3]. ····························(12分)
19.(12分)解:(1)①当时,函数为一次函数,设其解析式为,∵点和在函数图象上,
∴解得························(2分)