Предмет: Алгебра, автор: josephine27

Решить уравнение :
$2x + \sqrt{x ^{2} - 9} = x ^{2} + \sqrt{18 - 2x ^{2} } - 3$

Ответы

Автор ответа: yugolovin

$2x+\sqrt{x^2-9}=x^2+\sqrt{2(9-x^2)}-3.}$

ОДЗ: $\left \{ {{x^2-9\ge 0} \atop {9-x^2\ge 0}} \right. ;\ x^2-9=0; x=\pm 3.$

Итак, ОДЗ состоит из двух чисел - три и минус три. Проверим каждое из них. При подстановке x=3 получаем 6=6, а при подстановке x= - 3 получаем - 6=6. Вывод: подходит только x=3.

Ответ: 3

segirbaevbakdulet: Щдж

Предыдущий вопрос

Следующий вопрос

Похожие вопросы

Предмет: Русский язык, автор: kristina160476

??????лег на ветви ели Иглы за ночь побелели

1 год назад

Предмет: Английский язык, автор: Александра55440

Прочитайте тексты и установите соответствие между текстами А–G и заголовками 1–8. Запишите свои ответы в таблицу. Используйте каждую цифру только один раз. В задании есть один лишний заголовок.
A)English is basically a Germanic language with a lot of Latin words in it. In simple terms, that means that the grammar and many of the most frequent words are Germanic, and the more formal or technical vocabulary is Latinate. The linguistic mixture is a result of historical events. But the simple historical facts appear not to explain everything about the development of the language. One interesting question is why the British did not learn Latin from the Romans.
B) It came as a surprise to many people when a survey showed that 172 languages were spoken by children in London schools: Chinese, Turkish, Italian, Spanish, Punjabi and others. Some of these, like the West African language Ga, only have a couple of speakers. But others, like Punjabi, are quite significant linguistic community, with their own radio programmes and newspapers, and classes for children – to ensure that they don’t forget the language of their grandparents.
C) A nasty shock awaits many visitors to Britain. Imagine you have learnt English for years, you can read newspapers and you have no problem following the television, but when you go into a shop in Newcastle you can’t understand a word they are saying. It is the accent, mostly the vowels, which gives the visitor a problem in the shop. Some accents are so strong that they present problems for British people, too. Intonation patterns also differ between regions.
D) Billions of people speak English, two-thirds of the planet’s scientists write in English, and over 80% of the world’s electronic information is stored in English. But not all the British are really self-satisfied about the status of their language. But they are quite well aware that today it is out of their hands: the reasons for the popularity of English are either lost in history, or something to do with the superpower on the other side of the Atlantic.
E) Let’s look at the speech of young people in Britain. Here we can find several interesting developments. One is a spread of a light London accent over much of the country. Another is an openness, through the media, to American and Australian influences. The Australian effect is quite recent, and the results from the huge popularity of Australian TV soap operas. It is the phrases, idioms and grammatical forms which are catching.
1) Languages spoken in Britain
2) The origin of English
3) Modern language tendencies
4) Regional varieties of English
5) English in Australia
6) Global English

1 год назад

Предмет: Английский язык, автор: melnichuk1995