题目

某时刻一质点位于O点，受到两个力的作用，F1=3N方向东偏北450， F2=4N，方向西偏北300．请在下图中做出F1 、F2的力的图示并用作图法求出这两个力的合力F大小和方向．（要求标明标度，不必写出求F的过程） 答案：作图··············································································································· (2分) F=4.3N(4.1～4.5均可)······································································�如图，正方形的边长为4，点的坐标为（-1，1），平行于轴，则点的坐标为 __________.