Cho 0o < x < 90o, CM các biểu thức sau không phụ thuộc vào biến:

1) \(\left(\sin^4x+\cos^4x-1\right).\left(\tan^2x+\cot^2x+2\right)\)

Cho 0o < x < 90o, CM các biểu thức sau không phụ thuộc vào biến:

\(\dfrac{\tan^2x-\cos^2x}{\sin^2x}+\dfrac{\cot^2x-\sin^2x}{\cos^2x}\)

Cho 0o < x < 90o, CM các biểu thức sau không phụ thuộc vào biến:

sin\(^6\)x +cos\(^6\)x-2sin\(^4\)x - cos\(^4\)x + sin\(^2\)x

VI/. Supply the correct tense of the verb.

1. They are used to………………….. (live) in this remote area. 2. He can't speak English without ………………….. (make) mistakes.

3. We heard him………………….. (sing) in the next room.

4. She noticed something ………………….. (burn) in the kitchen

. 5. They decided ………………….. (have) a picnic in the mountain

7. Hamlet, ………………….. (write) by William Shakespeare, is a famous tragedy

. 8. They told me………………….. (not tell) their children about that.

9. I wish I………………….. (be) at home yesterday to meet her.

10. If the test………………….. (be) longer, I might have failed.

V. Give right formation of the following words

1. English spelling presents special … … for foreign learners. ( difficult)

2. The school is performing well, but we recognize the need for further … … .( improve)

3. Let me introduce you a … … university. I think it’s really reliable. ( repute)

4. We placed … … in a number of national newspapers. ( advertise)

5. If you want to attend the course, you must pass the … … examination. ( write)

6. We couldn’t go out because it rained ………….. . (continue)

7. The professor criticized his students both …………….and individually. (collect)

8. His teacher found that she could do the ………..with no trouble at all. (calculate)

9. After the war, many soldiers turned to live in ……………… . (retire)

10. Should we …………….. this invention. (public)

Choose the best answer to complete these following sentences:

1) They .......... in that house for several months.

A: live B: are living C: Living D: have lived

2) It is rains heavily , ............I can't go to the movie with you .

A: because B: and C: so D: but

3) My father ..........teaching in a small village 10 year ago.

A: is starting B: started C: starts D: has started

4) Minh wishes he ......... a new bike .

A: has B: would have C: had D:will have

5) I wish you .......... it again . A:don't do B:won't do C: didn't do D: wouldn't do

6) I can't go to the park with you ............ it is raining .

A:so B:because C:and D:but

7) He wishes he .......... speak English well.

A: Can B: could C: would D: will

8) It was an ...........day. A: enjoy B: enjoyable C:enjoyment D:enjoyablly

9) They walked . half an hour to reach the village.

A:in B:at C:to D:for

10)My village lies near the ..........of the moutain and by the river .

A) foot B: leg C: feet D: hand

11) She has just taken the exemination ..... Maths .

A: for B:at C:on D: in

12)The telephne was ..............by Alexander Bell.

A) invent B: invented C:inventing D:inventor

13) I'm very proud.......... my school.

A: from B;at C: of D:off

14) She did the test very well and I did ..........

A: even B: also C: too D: so

15) He worked very hard, ............. he passed the exem easily.

A:and B:so C:but D:because

16) On the .... to the village , we saw a big hotel.

A: way B: entrance C: direction D:mountain

17) I knew her ............. I was a child.

A: since B: until C: while D:when

18)Hurry up , or you won't ..... the last bus .

A: miss B: take C: catch D:go

19)He can swim and ............ can I.

A: to B: too C: so D:such

20)Let's wait ............ the rain stops.

A: before B: after C: until D:when