Question

设方程x²+x+m=0的解集为A,方程x²+2mx+m²-m+2=0的解集为B,若A∪B≠空集,求实数m的范围.敷

Answer 1

若A并B=空集,则有:

x^2+x+m=0 --> delta1=1-4m m>1/4

x^2+2mx+m^2-m+2=0--->delta2=4m^2-4m^2+4m-8=4m-8 m