① 记 (m,0), 则 m=[3-(-2)]/2=5/2, M(5/2,0)② M(-5/2,0), 或 M(0,5) 或 M(0,-5)图2: 记 ∠POD = t, 则 ∠AOP = 90°+t, ∠AOE = 45°+t/2, ∠DOE = 45°-t/2, ∠OPD = 90°-t, ∠OPD/(∠DOE) = 2。