Question

设集合A={x｜｜x-2｜≤2,x∈R},B={y｜y=-x²,-1≤x≤2},则(A∩B)等于

A.R                B.{x｜x∈R且x≠0}          C.{0}             D.

Answer 1

解析：由｜x-2｜≤2,得0≤x≤4,即A={x｜0≤x≤4}.

由y=-x²,-1≤x≤2,得-4≤y≤0,即B={y｜-4≤y≤0}.

∴A∩B={0}.∴(A∩B)={x｜x∈R且x≠0}.故选B.

答案：B