Найдите количество n членов геометрической прогрессии, в какой b1 = 3/2, bn = 768, Sn = 1534,5.

Найдите количество n членов геометрической прогрессии, в какой b1 = 3/2, bn = 768, Sn = 1534,5. (Помогите, пожалуйста).
- Предмет:
  Математика
- Автор:
  jamievmz5
- 5 лет назад

Ответы 1

Sn = b1*(1-q^n)/(1-q) = (b1 - bn*q)(1-q);Sn * (1-q) = (b1 - bn*q)Sn - Sn*q = b1 - bn*qSn - b1 = Sn*q - bn*qSn - b1 = q * (Sn - bn)q = (Sn - b1)/(Sn - bn) = (1534,5 - 1,5)/(1534,5 - 768) = 2bn = b1 * q^(n-1)768 = 1,5 * 2^(n-1)512 = 2^(n-1)2^9 = 2^(n-1)n = 10
- Автор:
  redfiwf
- 5 лет назад
- 0
Добавить свой ответ

Еще вопросы

Упростить вырождение 4a^-1/ y^2•y^5/12a^-3
Если ay не равно 0
- Предмет:
  Алгебра
- Автор:
  jaliyahnkgt
- 5 лет назад
- Ответов:
  
  1
- Смотреть
ПОМОГИТЕ! У меня сегодня сдача по топикам. Кто нибудь отправьте короткие топики. Я вас умаляю ПОМОГИТЕ.Student Card
Task 1 (1,5-2 minutes)
Give a talk about climate.
Remember to say:
1) what is climate in fact
2) if climate is the same in this or that part of the world, if it changes and how it happens
3) what the greenhouse effect is
4) how the greenhouse effect can influence the climate on the planet in future
5) if our planet needs protection
Student Card
Task 1 (1,5-2 minutes)
Give a talk about the environmental problems
Remember to say:
1) what the word “environment” means
2) what the most serious environmental problems are
3) what makes sea water dangerous nowadays
4) where air pollution mostly comes from
5) what people should do to solve these problems
Student Card
Task 1 (1,5-2 minutes)
Give a talk about England
Remember to say:
1) what the capital of England is and how big it is compared with other cities
2) what the regions of England are
3) what each region is famous for, what their main attractions are
4) what parts of England you would like to visit and why
Student Card
Task 1 (1,5-2 minutes)
Give a talk about Royal London
Remember to say:
1) what places in London are connected with the Crown
2) which building is the official residence of Queen Elizabeth II
3) how many royal parks there are in London (name some of them)
4) what Royal processions are usually held in London
5) which of the famous British kings and queens you can name; why they are remembered
Student Card
Task 1 (1,5-2 minutes)
Give a talk about Scotland
Remember to say:
1) into what parts Scotland is divided geographically
2) what the two great cities are
3) what they are famous for
4) what the main attractions of Edinburgh are
5) if you would like to visit Scotland and why
Student Card
Task 1 (1,5-2 minutes)
Give a talk about Wales.
Remember to say:
1) where Wales is situated
2) what the symbols of Wales are
3) what the two national languages are
4) what the main attractions are in Wales
5) what the national game of Wales is
Student Card
Task 1 (1,5-2 minutes)
Give a talk about the USA and its people
Remember to say:
1) where the USA situated
2) how many states there are in this country
3) what mighty rivers and mountain chains you can name
4) what the most famous places are to enjoy the beauty and the power of wild America
5) why people call the USA “a big melting pot”
Student Card
Task 1 (1,5-2 minutes)
Give a talk about political system of the USA
Remember to say:
1) when the Constitution was written and who wrote it
2) what the three brunches of the US government are
3) what the changes to the constitution are
4) how many amendments to the Constitution there are
Student Car
Give a talk about William Shakespeare.
Remember to say:
1) when and where he was born
2) what he was famous for
3) who was his wife and children
4) why he takes a special place in the history of theatre
5) what great plays he wrote
- Предмет:
  Английский язык
- Автор:
  durán0mqu
- 5 лет назад
- Ответов:
  
  4
- Смотреть
Найдите описание собачки. Допишите предложение . Подчеркните эпитеты
- Предмет:
  Литература
- Автор:
  pierreavhp
- 5 лет назад
- Ответов:
  
  4
- Смотреть
назовите звенья рефлекторной дуги слюноотделительного рефлекса
- Предмет:
  Биология
- Автор:
  charliecarpenter
- 5 лет назад
- Ответов:
  
  1
- Смотреть

Найдите количество n членов геометрической прогрессии, в какой b1 = 3/2, bn = 768, Sn = 1534,5. (Помогите, пожалуйста).

Ответы 1

Топ пользователей