mira1212 Posted January 3, 2017 Report Share Posted January 3, 2017 HI ALL, THIS IS FROM THE VECTORS UNIT, THE ANSWER IS -1,-2, AND WE HAVE TO FIND D CAN SOMEONE HELP? Reply Link to post Share on other sites More sharing options...
Vioh Posted January 3, 2017 Report Share Posted January 3, 2017 When dealing with vectors, it might be a good idea to always think of the points as vectors with respect to the origin of the coordinate system. Let's call this origin point O. In other words, the vector OA is (1,4). The vector OB is (6,5), and finally, OC is (4,-1). Since the picture clearly shows a parallelogram, so the vector AB must be parallel (and in the same direction) as the vector DC (in other words, AB = DC). As you probably know from theory (or just by simply drawing all the points on the coordinate system), we have AB = OB - OA, and DC = OC - OD. Thus: OB - OA = OC - OD = (6,5) - (1,4) = (5,1) = OC - OD --> OD = OC - (5,1) = (4,-1) - (5,1) = (-1,-2) which is the answer. It might be a little difficult to grasp at first, but if you draw everything out on the coordinate system (together with the origin), it becomes incredibly easy to understand. Reply Link to post Share on other sites More sharing options...
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