设U=R,M={m│方程mx^2-x+1=0有实根},N={n│方程x^2-nx+1=0有实根},求CuM∩N

问题描述:

设U=R,M={m│方程mx^2-x+1=0有实根},N={n│方程x^2-nx+1=0有实根},求CuM∩N

M={m│方程mx^2-x+1=0有实根}
△=1-4m≥0
m≥1/4 or m=0
N={n│方程x^2-nx+1=0有实根}
△=n^2-4≥0
n≥2 or n≤-2
M∩N=[2,+∞)
CuM∩N=(-∞,2)