Cho phương trình ![img1](https://cungthi.online/upload/questionbank3/eduquestion/2018541757312345570/obj2018541757312345570488075_images/obj2018541757312345570488075_img1.png)
. Với giá trị nào của
thì
có
nghiệm
,
thoả
.
![img1](https://cungthi.online/upload/questionbank3/eduquestion/2018541757312345570/obj2018541757312345570488075_images/obj2018541757312345570488075_img1.png)
![img2](https://cungthi.online/upload/questionbank3/eduquestion/2018541757312345570/obj2018541757312345570488075_images/obj2018541757312345570488075_img2.png)
![img3](https://cungthi.online/upload/questionbank3/eduquestion/2018541757312345570/obj2018541757312345570488075_images/obj2018541757312345570488075_img3.png)
![img4](https://cungthi.online/upload/questionbank3/eduquestion/2018541757312345570/obj2018541757312345570488075_images/obj2018541757312345570488075_img4.png)
![img5](https://cungthi.online/upload/questionbank3/eduquestion/2018541757312345570/obj2018541757312345570488075_images/obj2018541757312345570488075_img5.png)
![img6](https://cungthi.online/upload/questionbank3/eduquestion/2018541757312345570/obj2018541757312345570488075_images/obj2018541757312345570488075_img6.png)
![img7](https://cungthi.online/upload/questionbank3/eduquestion/2018541757312345570/obj2018541757312345570488075_images/obj2018541757312345570488075_img7.png)
![img8](https://cungthi.online/upload/questionbank3/eduquestion/2018541757312345570/obj2018541757312345570488075_images/obj2018541757312345570488075_img8.png)
A.
B.
C.
hoặc
.
D.
và
.
Đáp án và lời giải
Đáp án:A
Lời giải:
Phân tích:
.
Vậy đáp án đúng là A.