2025年重庆中考数学A卷真题(网络版)
本题考查了函数的解析式与定义域。
首先要求求函数f(x)的定义域,将x的取值范围分成n个小组,分别求出每个小组定义域的中位数,再求出小组数n的中位数,即可得到函数f(x)的定义域。
解答如下:
第一组:将x的取值范围分成4个小组,分别求出每个小组定义域的中位数,即:
当x=2时,定义域为{2, 4, 6, 8}
当x=3时,定义域为{3, 5, 7, 9}
当x=4时,定义域为{4, 6, 8, 10}
当x=5时,定义域为{5, 7, 9, 11}
当x=6时,定义域为{6, 8, 10, 12}
当x=7时,定义域为{7, 9, 11, 13}
当x=8时,定义域为{8, 10, 12, 14}
当x=9时,定义域为{9, 11, 13, 15}
当x=10时,定义域为{10, 12, 14, 16}
当x=11时,定义域为{11, 13, 15, 17}
当x=12时,定义域为{12, 14, 16, 18}
当x=13时,定义域为{13, 15, 17, 19}
当x=14时,定义域为{14, 16, 18, 20}
当x=15时,定义域为{15, 17, 19, 21}
当x=16时,定义域为{16, 18, 20, 22}
当x=17时,定义域为{17, 19, 21, 23}
当x=18时,定义域为{18, 20, 22, 24}
当x=19时,定义域为{19, 21, 23, 25}
当x=20时,定义域为{20, 22, 24, 26}
当x=21时,定义域为{21, 23, 25, 27}
当x=22时,定义域为{22, 24, 26, 28}
当x=23时,定义域为{23, 25, 27, 29}
当x=24时,定义域为{24, 25, 27, 30}
当x=25时,定义域为{25, 26, 28, 30}
第二组:要求函数g(x)的定义域,将x的取值范围分成n个小组,分别求出每个小组定义域的中位数,再求出小组数n的中位数,即可得到函数g(x)的定义域。
解答如下:
第一组:将x的取值范围分成10个小组,分别求出每个小组定义域的中位数,即:
当x=2时,定义域为{2, 4, 6, 8, 10, 12, 14, 16, 18}
当x=3时,定义域为{3, 5, 7, 9, 11, 13, 15, 17, 19}
当x=4时,定义域为{4, 6, 8, 10, 12, 14, 16, 18, 20}
当x=5时,定义域为{5, 7, 9, 11, 13, 15, 17, 19, 21}
当x=6时,定义域为{6, 8, 10, 12, 14, 16, 18, 20, 22}
当x=7时,定义域为{7, 9, 11, 13, 15, 17, 19, 21, 23}
当x=8时,定义域为{8, 10, 12, 14, 16, 18, 20, 22, 24}
当x=9时,定义域为{9, 11, 13, 15, 17, 19, 21, 23, 25}
当x=10时,定义域为{10, 12, 14, 16, 18, 20, 22, 24, 26}
当x=11时,定义域为{11, 13, 15, 17, 19, 21, 23, 25, 27}
当x=12时,定义域为{12, 14, 16, 18, 20, 22, 24, 26, 28}
当x=13时,定义域为{13, 15, 17, 19, 21, 23, 25, 27, 29}
当x=14时,定义域为{14, 16, 18, 20, 22, 24, 26, 28, 30}
当x=15时,定义域为{15, 17, 19, 21, 23, 25, 27, 29, 31}
当x=16时,定义域为{16, 18, 20, 22, 24, 26, 28, 30, 32}
当x=17时,定义域为