已知集合A={α|2kπ≤α≤(2k+1)πk∈Z}B={α|-4≤α≤4}则A∩B为（）A.B.{α|-4≤α≤π}C.{α|0≤α≤π}D.{α|-4≤α≤-π}∪{α|0≤α≤π}

Question

已知集合A={α|2kπ≤α≤(2k+1)π k∈Z} B={α|-4≤α≤4} 则A∩B为（    ）

A.                                         B.{α|-4≤α≤π}

C.{α|0≤α≤π}                         D.{α|-4≤α≤-π}∪{α|0≤α≤π}

Answer 1

解析：当k=0时，A={α|0≤α≤π}，此时A∩B={α|0≤α≤π}.当k=-1时A={α|-2π≤α≤-π}，此时，A∩B={α|-4≤α≤-π}.于是A∩B={α|-4≤α≤-π}∪{α|0≤α≤π}.

答案：D