已知全集U=R,集合M={x丨x≤3},N={x丨x<1},求m交n,(cum)并N,(cum)交（cun)已知全集U=R,集合M={x丨x≤3},N={x丨x
问题描述：
已知全集U=R,集合M={x丨x≤3},N={x丨x<1},求m交n,(cum)并N,(cum)交（cun)
已知全集U=R,集合M={x丨x≤3},N={x丨x
答
m交n=={x丨x3}并{x丨x3或x(cum)交（cun)={x丨x>3}交{x丨x>=1}={x丨x>3}
答
M∩N={X|x3} cun={x|x≥1}
(cum)并N={x|x3}
(cum)交（cun)={x|x>3}