user-avatar
bao.superz
2 năm trước
Chứng minh biểu thức luôn dương hoặc âm với mọi gía trị của x 1. x^2 + x + 1> 0 với mọi x 2. x^2 + 9x + 10 > 0 với mọi x 3. x- x^2 - 1 < 0 với mọi x 4. 4x- x^2 - 5 < 0 với mọi x 5. -x^2 + 10x- 35 < 0 với mọi x
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

Question 50. We’ll play tennis and ___________ we’ll have lunch.  A. so   B. after   C. immediately   D. then Question 51  Two thousand miles  ___________ a long distance. A. are   B. make   C. have   D. is Question 52. Is swimming under water very difficult ?  No, it’s just a matter ___________ able to control your breathing A. to be   B. of being   C. that you are    D. being Question 53. Now men and women remain single longer than they once ___________ A. do   B. did   C. doing   D. were done Question 54. Mexico is the most popular vacation _____ for people from The United States.  A. target   B. connection   C. departure   D. destination Question 55. When it began to rain, they ___________ in the yard A. played   B. were playing   C. have played   D. had played Question 56 . We love HANOI, ___________ in the spring. A. mostly   B. most   C. especially   D. specially Question 57. The cost of living has ___________ over 10 percent in the past years. A. raised    B. raise   C. risen   D. rising Question 58. We lived in that __________ on the corner. A. house brick small old B. old house brick small C. brick small old house D. small old brick house Question 59. They can’t work. They are too tired A. When they are too tired, they can work   B. Because they can’t work, they’re too tired  C. They are too tired that they can’t work  D. They are too tired to work Question 60.  To the best of my ___________ , he married an Irish girl  A. retention   B. recall   C. memory    D. recollection Question 61. Ceylon is ___________the South of India. A. to   B. in   C. at    D. below Question 62. Come with me. I’m seeing “ The killer” tomorrow. ___________ A. Are you?   B. Do you?   C. Will you?   D. Shall you? Question 63. No one has ever asked me that question before.  In the passive voice: A. That question has ever been asked me by no one before.    B. That question has never been asked me before by anyone    C. I have not ever been asked that question before    D. I have never been asked that question before Question 64. If he hadn’t stayed up late yesterday ,____________ now. A.he wouldn’t be tired B. he was not tired C. he would not have been tired D. he is not tired Question 65. Why did Berth ask you ___________ a bicycle ? A. that if you had   B. do you have   C. that you had   D. if you had Question 66. . Are you looking for anything in ___________ ? A. special   B. detail   C. peculiar   D. particular Question 67. These chairs are ___________ better than the others. A. as   B. very   C. much   D. either Question 68. __________that no one would ask for tips. A.The tourists found it strange B.The tourists found strange C.The tourist were strange to find D.It found strange tourists Question 69. Our teacher said “The Second world war broke out in 1939”.  Indirect speech: ___________   A. Our teacher told us that the Second world war had broken out in 1939   B. Our teacher told that the Second world had broken out in 1939   C. Our teacher said that the Second world war broke out in 1939   D. Our teacher said us that the Second world war had broke out in 1939 Question 70. Dr Sales is the person ___________. A.in that I don't have much confidence B. in whom I don't have much confidence C. I don't have much confidence D. whom I don't have much confidence in him

2018 © Loga - Không Ngừng Sáng Tạo - Bùng Cháy Đam Mê
Loga Team