2019版数学人教B版必修1训练:1.2.1 集合之间的关系
2019版数学人教B版必修1训练:1.2.1 集合之间的关系第3页

  当B={2}时,1/(m"-" 1)=2,得m=3/2;

  当B={3}时,1/(m"-" 1)=3,得m=4/3.

  所以M={1"," 3/2 "," 4/3}.

答案{1"," 3/2 "," 4/3}

★11已知集合A={x|0

分析集合B是关于x的不等式m

解因为B⊆A,所以B=⌀或B≠⌀.

  当B=⌀时,⌀⊆A,满足题意,

  则有m≥4-m,此时m≥2;

  当B≠⌀时,则有{■(m<4"-" m"," @m≥0"," @4"-" m≤3"," )┤解得1≤m<2.

  综上可知,实数m满足的条件是1≤m<2或m≥2,即m≥1.