Cho hai điểm
,
thuộc đồ thị hàm số
trên đoạn
Các điểm
,
thuộc trục
thỏa mãn
là hình chữ nhật và
. Độ dài cạnh
bằng
![img1](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img1.png)
![img2](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img2.png)
![img3](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img3.png)
![img4](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img4.png)
![img5](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img5.png)
![img6](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img6.png)
![img7](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img7.png)
![img8](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img8.png)
![img9](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img9.png)
![img10](https://cungthi.online/upload/questionbank3_20201220/eduquestion/2019081766593382829/obj2019081766593382829633912_images/obj2019081766593382829633912_img10.png)
A.
.
B.
1.
C.
.
D.
.
Đáp án và lời giải
Đáp án:C
Lời giải:
Phân tích: Gọi ,
. Ta có:
Thay
vào
, ta được:
Do
nên
. Vậy đáp án đúng là C.