\(\dfrac{cos\alpha}{1+sin\alpha}+tan\alpha\)

\(=\dfrac{cos\alpha}{1+sin\alpha}+\dfrac{sin\alpha}{cos\alpha}\)

\(=\dfrac{cos^2\alpha+sin\alpha\left(1+sin\alpha\right)}{\left(1+sin\alpha\right)cos\alpha}\)

\(=\dfrac{cos^2\alpha+sin^2\alpha+sin\alpha}{\left(1+sin\alpha\right)cos\alpha}\)

\(=\dfrac{1+sin\alpha}{\left(1+sin\alpha\right)cos\alpha}\)

\(=\dfrac{1}{cos\alpha}\)

C. 256

 \(A=\left(sin^2\alpha+cos^2\alpha\right)^2=1\)

6. climbing

7. exercising

8. dancing

em làm đúng 5 câu đầu rồi nhx còn thiếu 3 câu cuối

1. This is the first time I have participated in a community.

2. They have provided the elderly with cheap bus tickets some days ago.

3. Jack is not rick but he gives the beggar some money.

4. The students last participated in the clean-up programme in 2018.

5. I have never seen the dirtiest beach before.

6. Let's join a programme that helps the elderly.

7. There are too many advertisements and graffiti in the wall.

8. He started collecting clothes for street kids two years ago.

câu 17 sửa từ Bindley thành Bingley nha

11. "How do you like my new dress?" - She said to John.

12. He wanted to know how long it had been since Bob left that city.

13. The office manager wondered why he hadn't got a computer before.

14. Ann pleaded with her friend not to drive so fast.

15. Mary asked John not to tell anyone her new address.

16. Mrs. Smith asked where the station car-park was.

17. The nurse asked Mrs. Bindley how old the little boy was.

18. He advised us to go by train.

8. as quietly as

9. farther

10. most popular

25. My mother said me that it's high time I woke up.

26. The teacher told his students to listen to him and not to make noise.

28. Mrs Hoa told us to do our homework everyday.

29. The household asked me not to go out alone at night.

30. The man asked Mr Linh what his son wanted to learn.

31. Liz asked me if I lived there.

32. She said that he didn't buy that book.

33. The teacher said that all the homework had to be done carefully.