Phương trình lượng giác
có nghiệm là:
A.
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848282052_images/obj20192604842221486848282052_img1.png)
B.
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848390560_images/obj20192604842221486848390560_img1.png)
C.
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848471011_images/obj20192604842221486848471011_img1.png)
D.
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848870399_images/obj20192604842221486848870399_img1.png)
Đáp án và lời giải
Đáp án:B
Lời giải:Chọn B
![img1](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848362433_images/obj20192604842221486848362433_img1.png)
![img2](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848362433_images/obj20192604842221486848362433_img2.png)
![img3](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848362433_images/obj20192604842221486848362433_img3.png)
.
Vậy đáp án đúng là B.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848362433_images/obj20192604842221486848362433_img1.png)
![img2](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848362433_images/obj20192604842221486848362433_img2.png)
![img3](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848362433_images/obj20192604842221486848362433_img3.png)
![img4](https://cungthi.online/upload/questionbank3/eduquestion/20192604842221486848/obj20192604842221486848362433_images/obj20192604842221486848362433_img4.png)