Question

已知集合A={0,1}，B={y｜x²+y²=1,x∈A}，则(    )

A.A=B                B.AB                 C.BA                D.BA

Answer 1

解析：∵x∈A，∴x=0,或x=1.又∵x²+y²=1，∴x=0，y=±1,或x=1，y=0.∴B={-1,0,1}.∴AB.故选B．

答案：B