Lời giải:
Trong khoảng $[\frac{-\pi}{2}; \frac{-\pi}{3}]$ $x$ càng lớn thì $\sin x$ càng lớn 

Do đó:

$y_{\min}=y(\frac{-\pi}{2})=-1$ 

$y_{\max}=y(\frac{-\pi}{3})=\frac{-\sqrt{3}}{2}$

chu nho qua ban oi

13D

15A

11. Linh said she preferred texting to sending letters.

12. My mother said she hoped there wouldn't be traffic jams in 20 years.

13. The teacher asked what a language barrier was.

14. Tom wondered if robots would replace teachers in class. 

15. Jerry said the night before, he had dreamt of flying to Vietnam.

Linh said she preferred texting to sending letters.

My mother said she hoped there wouldn't be traffic jams in 20 years' time.

The teacher asked what a language barrier was.

Tom wondered if robots would replace teachers in class.

Jerry said she had dreamt of flying to Venus the night before.

11. Linh said that she prefered texting to send letter

12. My mother said that she hoped there wouldn't be traffic jams in 20 years time

13. The teacher asked what a language barrier was

14. Tom wondered if robots would replace teachers in classes

15. Jerry said that she hard dreamt of flying to Venus the day before

câu 17. c

câu 18. a

câu 9. d

câu 15. a

câu 12. b

câu 7. 

a, b, g, i, h

Câu 15: 

Hàm số y=ax+b, với a<>0 nghịch biến trên R khi a<0

Từ đó bạn thay vào thôi

Câu 14: 

Bạn cần biến đổi về dạng y=ax+b(a<>0) rồi sau đó lần lượt thay x=0 và y=0 vào là ra

*cái tên* me too :((