Giá trị của
bằng:
A.
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2020350652434655102/obj2020350652434655102451607_images/obj2020350652434655102451607_img1.png)
B.
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2020350652434655102/obj2020350652434655102703684_images/obj2020350652434655102703684_img1.png)
C. 0
D.
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2020350652434655102/obj2020350652434655102247305_images/obj2020350652434655102247305_img1.png)
Đáp án và lời giải
Đáp án:D
Lời giải:
Ta có:
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2020350652434655102/obj2020350652434655102698141_images/obj2020350652434655102698141_img1.png)