cho đường tròn (o) ,diểm A nằm ngoài đường tròn , từ A vẽ tiếp tuyến AB, AC (B,C là tiếp điểm).gọi H là giao điểm của AO và BC a, CM : OA vuông góc vs BC tai H B. cm : AE.AD=AH .AC

Cho hình chóp S.ABCD, ABCD là hình bình hành tâm O. Gọi M, N, P lần lượt là trung điểm của SA, SB, SD. a. Chứng minh: MN // (ABCD) b. Chứng minh: MP // (ABCD) c. Chứng minh: NP // (ABCD) d. MO song song với những mặt phẳng nào? Vì sao? Giúp mình bài này vs

Cho hình bên biết diện tích hình tam giác AMC là 7cm2 ,MC = 3,5cm , BM = 6cm .Tính diện tích tam giác ABM

Một viên đạn khối lượng 50 g bay ngang với vận tốc không đổi 200 m/s. Viên đạn đến đâm vào một tấm gổ dày và chui sâu vào gỗ rồi dừng lại. Xác định công của lực cản của gỗ tác dụng lên viên đạn

Lm giúp mình bài 1 b và c nha mơn mn

các bạn làm phần bài tập dùm mình ạ

Giúp mình vs nhé. Mình cần gấp

a, Chứng minh (d): y=x-1/2 và (P): y=x^2/2 luôn luôn tiếp xúc nhau. b, Tìm m để (d): y=mx-1 và (P): y=x^2 tiếp xúc nhau.

II/ EXERCISES A. Complete the sentences below, using the correct form or tense of the verbs in brackets 1. I enjoy (fish ) …………………because it (be) ………………. relaxing . 2. My uncle likes (live) ……………………. in the countryside . I think he (move) ………………….. to his hometown next year . 3. What ………. your sister often ( do) ……………… in her free time ? She loves (read)…………………… . 4. They (live) …………….. in Ho Chi Minh City for ten years . Now they (live) …………………….. in Ha Noi 5. He (go) ………………. to the bookstore yesterday and (buy) ……………….. some interesting books. 6. …………..you (finish) …………… your homework yet ? Yes, I (finish) …………… it ten minutes ago . 7. Her brother (work) ………………… in that company since he (graduate) from the University. 8. She always (get) …………… up early every day but she (get) ………. up late yesterday morning. 9. It (not rain) …………………….. in the dry season . 10. Don’t worry . I (go) ……………… swimming with you tomorrow. B. Complete the second sentence so that it has a similar meaning to the first . 1. My sister has played the piano for five years . My sister started ……………………………………………. 2. I think cooking is interesting . I find …………………………………………….. 3. She couldn’t go to school because of the bad weather . Because ………………………………………………………………... 4. They started to learn English three years ago . They have ………………………………………………………… 5.Mr Nam intends to buy a new house in Nha Trang next week . Mr Nam ………………………………………………………. C.Underline and correct a mistake in each sentence below . 1. His father finds ice –skate difficult. ………………… 2. Why do you want to donate blood ? Because I am scared ……………………. 3. Lan enjoys to dance because she thinks dancing is interesting. ……………… 4. Mrs Nga has written that report since four days . …………………………. 5. We will to help the newcomers . ………………………… D.Match A and B to make meaningful sentences A B 1. Eat a lot of red fruits and vegetables A. because it helps to make you fitter and more active . 2.Stay outdoors more and do more physical activities. B. because they provide vitamin A which is good for your eyes . 3. Use eye -drops when you sit up late or when you return from a dusty area . C.or you will become weak and tired . 4. Don’t read or study when there is not enough light . D. to prevent your eyes from getting dry . 5. Eat enough calories . E . because it is harmful for your eyes . 1. …………….., 2………………..,3….…….,4….……….,5…………… E. Write full sentences using the suggested words and phrases given 1. My aunt/ uncle/ always/ give/ me / dolls/ special occasions . ………………………………………………………………………………………… 2. Hoa/ love / drawing / but she / say/ not continue/ hobby / the future . ………………………………………………………………………………………… 3. I hope/ the future/ my father/ teach me / how/ do eggshell carving . ………………………………………………………………………………………… 4. It/ be/ good idea/ eat/ different/ kinds / fruit/ vegetables / every day . ………………………………………………………………………………………… 5. Eat / fresh fruit/ be/ much better/ you / than / glass/ fruit juice. ……………………………………………………………………………………….. F. Choose the right words to complete the sentences. Homeless people, Stomachache, volunteer, temperature , sore throat, sunburn, arranging flowers , dancing, making pottery, community service 1. The activities that individuals or organizations do to benefit a community are called…………………………….. 2. You are a ………………………….. if you help other people willingly and without payment. 3. She looks very red. She was outdoors all day yesterday . I think she has ………………. 4. He ate some sea food . Now he feels sick . He says he has a ………………… 5. He was holding his neck . I think he has a …………………… 6. She looks so tired. She can’t keep her eyes open . She is very hot too. She has a ………………… . 7. My sister always buys flowers and puts them in a vase to display in the house . her hobby is …………………….. 8. If you spend most of your time making vases of bowls from clay. Your hobby is …………………………………. 9. His brother dances very well . His hobby is ……………………. 10. ……………………. are those who do not have a home and really need help. G. Complete the sentences with MORE / LESS 1. Eat ……………. Junk food . It makes you fat . 2. Wash your hands ……………… you will have less chance of catching flu . 3. Sleep …………….. but try to wake up at the usual time . Even at weekends. 4. Go outside …………….. if you need to go outside ,wear a sunhat . 5. Watch ……………. TV . Looking at the screen for too long hurts your eyes . làm ơn giúp mình

Giúp mik vs ạk ? Câu 4 đấy mng ơi ? Chưa học mà cô ra rồi