答案
-a≤x≤a
-b≤y≤b
-b≤x≤b
-a≤y≤a
A1(-a,0),A2(a,0)
A1(0,-a),A2(0,a)
B1(0,-b),B2(0,b)
B1(-b,0),B2(b,0)
2b
2a
x轴、y轴
原点
(0,1)