A:FeS
B:Fe2S3
C:FeO
D:FeS2
The first question is as as the second one. I can answer them easily.
已知函数f(x)=2x,x≥2x2-3,x<2若关于x的方程f(x)=k有三个不等的实根,则实数k的取值范围是( )