Trong mặt phẳng với hệ tọa độ Oxy cho tam giác ABC có trọng tâm
, biết
là trung điểm cạnh BC. Tọa độ đỉnh A là:
A.
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20190224883115128185/obj20190224883115128185286409_images/obj20190224883115128185286409_img1.png)
B.
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20190224883115128185/obj20190224883115128185270878_images/obj20190224883115128185270878_img1.png)
C.
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20190224883115128185/obj20190224883115128185574284_images/obj20190224883115128185574284_img1.png)
D.
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20190224883115128185/obj20190224883115128185558753_images/obj20190224883115128185558753_img1.png)
Đáp án và lời giải
Đáp án:D
Lời giải:
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/20190224883115128185/obj20190224883115128185450176_images/obj20190224883115128185450176_img1.png)