已知集合A＝｛x|x∧2-2x-3＜0｝B＝｛x|x^2-2mx+m^2-1≥0｝1.当m＝0时,求A∩B .2...

题目

已知集合A＝｛x|x∧2-2x-3＜0｝B＝｛x|x^2-2mx+m^2-1≥0｝1.当m＝0时,求A∩B .2...
已知集合A＝｛x|x∧2-2x-3＜0｝B＝｛x|x^2-2mx+m^2-1≥0｝1.当m＝0时,求A∩B .2.若Ac＝B,求实数m的取值范围.

答案

x²-2x-3＜0(x+1)(x-3)＜0解得-1＜x＜3即A＝｛x|-1＜x＜3｝m=0时B中方程为：x²-1≥0解得x≥1或x≤-1A∩B=｛x|1≤x＜3｝2、Ac=B所以B=｛x|x≥3或x≤1｝则1和3是方程x²-2mx+m²-1=0的二根即2m=1+3,...