已知集合A={（x,y)|y=ax+2},B={(x,y)|y=|x+1|},且A,B的交集是与个单元集,求实数a的取值范围.要数形结合B={(x,y)|y=|x+1|}画个y=|x+1|的草图看图:x=-1,y=0两边分别是k=-1和k=1的射线而A={（x,y)|y=ax+2...