Gọi Z0 Là Nghiệm Phức Có Phần ảo âm Của Phương Trình Z2−6z+13 ...

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Câu hỏi Toán học

Gọi z0 là nghiệm phức có phần ảo âm của phương trình z2−6z+13=0 . Tìm số phức w=z0+6z0+i . A.w=−245+75i . B.w=−245−75i . C.w=245−75i . D.w=245+75i . Đáp án và lời giải Đáp án:C Lời giải:Ta có: z2−6z+13=0⇔z=3+2iz=3−2i⇒z0=3−2i . Vậy, w=z0+6z0+i=245−75i .

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Bài tập trắc nghiệm 15 phút Phương trình bậc hai hệ số thực - Toán Học 12 - Đề số 3

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Một số câu hỏi khác cùng bài thi.

• Trên trường số phức  cho phương trình . Chọn khẳng định sai.

• (ĐỀ MINH HỌA 2016 – 2017) Kí hiệu z1, z2,  z3 và z4 là bốn nghiệm phức của phương trình z4−z2−12=0. Tính tổng T=z1+z2+z3+z4.
• Gọi z1 là nghiệm phức có phần ảo âm của phương trình z2+4z+20=0 . Tính giá trị biểu thức A=z13−16i.

• Gọi là nghiệm phức có phần ảo âm của phương trình . Khi đó giá trị biểu thức bằng

• Gọi là hai nghiệm phức của phương trình . Tính .         

• Kí hiệu  ,     là hai nghiệm phức của phương trình  + 4 = 0. Gọi M,N lần lượt là các điểm biểu diễn của ,   trên mặt phẳng tọa độ.Tính T = OM+ON với O là gốc tọa độ.  

• Trên tập số phức, cho phương trình: Chọn kết luận sai.

• Trên tập số phức, cho phương trình: Chọn kết luận sai.

• Gọi , là nghiệm của phương trình . Tính giá trị của biểu thức .

• Gọi z0 là nghiệm phức có phần ảo âm của phương trình z2−6z+13=0 . Tìm số phức w=z0+6z0+i .

Một số câu hỏi khác có thể bạn quan tâm.

• Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

  In the American colonies there was little money. England did not supply the colonies with coins and did not allow the colonies to make their own coins, except for the Massachusetts Bay Colony, which received permission for a short period in 1652 to make several kinds of silver coins. England wanted to keep money out of America as a means of controlling trade: America was forced to trade only with England if it did not have the money to buy products from other countries. The result during this pre-revolutionary period was that the colonists used various goods in place of money: beaver pelts, Indian wampum, and tobacco leaves were all commonly used substitutes for money. The colonists also made use of any foreign coins they could obtain. Dutch, Spanish, French, and English coins were all in use in the American colonies.

  During the Revolutionary War, funds were needed to finance the world, so each of the individual states and the Continental Congress issued paper money. So much of this paper money was printed that by the end of the war, almost no one would accept it. As a result, trade in goods and the use of foreign coins still flourished during this period.

  By the time the Revolutionary War had been won by the American colonists, the monetary system was in a state of total disarray. To remedy this situation, the new Constitution of the United States, approved in 1789, allowed Congress to issue money. The individual states could no longer have their own money supply. A few years later, the Coinage Act of 1792 made the dollar the official currency of the United States and put the country on a bimetallic standard. In this bimetallic system, both gold and silver were legal money, and the rate of exchange of silver to gold was fixed by the government at sixteen to one.

  The passage mainly discusses_____.

• Tìm x

  a. x - 101 = 25

  b. x:27=23

• Xà phòng hóa CH3COOC2H5 trong dung dịch NaOH đun nóng, thu được muối có công thức là

• A number of large insurance companies has their headquarters in the capital city.

• We have just visited disadvantaged children in an orphanage __________ in Bac Ninh Province.

• Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word for each of the blanks

  WORKING PARENTS

  Reliable studies have shown that children of parents who both go out to work have no more problems than children with one parent staying at home. My personal (36) _____ is that both parents should go out to work if they wish.

  Some parents invest so much in a career that they cannot bear to give it up. Others have to work because of (37)_____ necessity. There are several options when it comes to choosing childcare from child minders to the kind neighbour across the street.

  No (38) _____ how good the childcare may be, some children protest if their parents aren‟t around. Babies become dependent on parents and close family members, (39) _____ parents should make sure they allow plenty of time to help their child settle in with their new career.

  Remember: if parents want to (40) _____  the best for their children, it‟s not the quantity of time they spend with them, it‟s the quality that matters.

  Remember: if parents want to (40) _____ the best for their children, it‟s not the quantity of time they spend with them, it‟s the quality that matters.
• Theo pháp luật về đầu tư hiện hành của nước ta, Nhà đầu tư ra nước ngoài có các quyền gì?

• Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) OPPOSITE in meaning to the underlined word(s) in each of the following questions.

  There has been no discernible improvement in the noise levels since lorries were banned.

• Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions. 

            For many American university students, the weeklong spring break holiday means an endless party on a sunny beach in Florida or Mexico. In Panama City Beach, Florida, a city with a permanent population of around 36,000, more than half a million university students arrive during the month of March to play and party, making it the number one spring break destination in the United States.

            A weeklong drinking binge is not for anyone, however, and a growing number of American university students have found a way to make spring break matter. For them, joining or leading a group of volunteers to travel locally or internationally and work to alleviate problems such as poverty, homelessness, or environmental damage makes spring break a unique learning experience that university students can feel good about.

            During one spring break week, students at James Madison University in Virginia participated in 15 “alternative spring break” trips to nearby states, three others to more distant parts of the United States, and five international trips. One group of JMU students traveled to Bogalusa, Louisiana, to help rebuild homes damaged by Hurricane Katrina. Another group traveled to Mississippi to organize creative activities for children living in a homless shelter. One group of students did go to Florida, but not to lie on the sand.  They performed exhausting physical labor such as maintaining hiking trails and destroying invasive plant species that threaten the native Florida ecosystem.

            Students who participate in alternative spring break projects find them very rewarding. While most university students have to get their degrees before they can start helping people, student volunteers are able to help people now. On the other hand, the accommodations are far from glamorous. Students often sleep on the floor of a school or spend the week camping in tents. But students only pay around $250 for meals and transportation, which is much less than some of their peers spend to travel to more traditional spring break hotspots.

            Alternative spring break trips appear to be growing in popularity at universities across the United States. Students cite a number of reason for participating. Some appreciate the opportunity to socialize and meet new friends. Others want to exercise their beliefs about people’s obligation to serve humanity and make the world a better place whatever their reason, these students have discovered something that gives them rich rewards along with a break from school work.

  (“Active Skills for Reading: Book 2” by Neil J.Anderson – Thompson, 2007)

  How many university students travel to Panama Beach City every March for spring break?

• Con lắc lò xo dao động điều hòa theo phương nằm ngang. Khoảng thời gian giữa hai thời điểm liên tiếp động năng bằng thế năng là 0,2 s. Chu kì dao động của con lắc là:

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