若x3+2x2=−xx+2则x的取值范围是(  ) A.x<0 B.x≥-2 C.-2≤x≤0 D.-2<x<0

问题描述:

x3+2x2
=−x
x+2
则x的取值范围是(  )
A. x<0
B. x≥-2
C. -2≤x≤0
D. -2<x<0

x3+2x2
=−x
x+2
≥0,
∴-x≥0,x+2≥0,
∴-2≤x≤0,
故选C.