0°≤a≤120°,0°≤b≤120°
平面上:3点 O(0,0);A(2√ 3,-2√ 6);B(2√ 6,2√ 3)
点P是
→ → →
OP =OAcosa+OBsinb
求cosa,sinb取值范围,即: ?≤cosa≤?, ?≤sinb≤?
0°≤a≤120°,0°≤b≤120°
平面上:3点 O(0,0);A(2√ 3,-2√ 6);B(2√ 6,2√ 3)
点P是
→ → →
OP =OAcosa+OBsinb
求cosa,sinb取值范围,即: ?≤cosa≤?, ?≤sinb≤?