
3соs^2x-2sinxcosx-sin^2=0


Ответы на вопрос





Вроде бы решается так.




To solve the equation 3cos^2(x) - 2sin(x)cos(x) - sin^2(x) = 0, we can use trigonometric identities to simplify it and find the values of x.
Let's start by manipulating the equation:
3cos^2(x) - 2sin(x)cos(x) - sin^2(x) = 0
We know that cos^2(x) + sin^2(x) = 1, so we can substitute cos^2(x) with 1 - sin^2(x):
3(1 - sin^2(x)) - 2sin(x)cos(x) - sin^2(x) = 0
Expanding the equation:
3 - 3sin^2(x) - 2sin(x)cos(x) - sin^2(x) = 0
Combining like terms:
4 - 4sin^2(x) - 2sin(x)cos(x) = 0
Rearranging the terms:
-4sin^2(x) - 2sin(x)cos(x) + 4 = 0
Now, let's factor out -2 from the first two terms:
-2(2sin^2(x) + sin(x)cos(x)) + 4 = 0
Factoring out sin(x) from the parentheses:
-2sin(x)(2sin(x) + cos(x)) + 4 = 0
Dividing the equation by -2:
sin(x)(2sin(x) + cos(x)) - 2 = 0
So, we have:
sin(x)(2sin(x) + cos(x)) - 2 = 0
Now, we can solve this equation by setting each factor equal to zero:
sin(x) = 0 (Equation 1) 2sin(x) + cos(x) = 2 (Equation 2)
Let's solve Equation 1:
sin(x) = 0
The solutions for this equation are x = 0, π, 2π, 3π, etc.
Now, let's solve Equation 2:
2sin(x) + cos(x) = 2
To solve this equation, we can square both sides:
(2sin(x) + cos(x))^2 = 2^2
Expanding and simplifying:
4sin^2(x) + 4sin(x)cos(x) + cos^2(x) = 4
Using the trigonometric identity cos^2(x) + sin^2(x) = 1:
4sin^2(x) + 4sin(x)cos(x) + 1 - sin^2(x) = 4
Simplifying further:
3sin^2(x) + 4sin(x)cos(x) - 3 = 0
We can substitute 1 - cos^2(x) for sin^2(x):
3(1 - cos^2(x)) + 4sin(x)cos(x) - 3 = 0
Expanding:
3 - 3cos^2(x) + 4sin(x)cos(x) - 3 = 0
-3cos^2(x) + 4sin(x)cos(x) = 0
Factor out cos(x):
cos(x)(-3cos(x) + 4sin(x)) = 0
So, we have two possibilities:
- cos(x) = 0
- -3cos(x) + 4sin(x) = 0
Let's solve each possibility:
- cos(x) = 0
The solutions for this equation are x = π/2, 3π/2,


Топ вопросов за вчера в категории Алгебра
Последние заданные вопросы в категории Алгебра
-
Математика
-
Литература
-
Алгебра
-
Русский язык
-
Геометрия
-
Английский язык
-
Химия
-
Физика
-
Биология
-
Другие предметы
-
История
-
Обществознание
-
Окружающий мир
-
География
-
Українська мова
-
Информатика
-
Українська література
-
Қазақ тiлi
-
Экономика
-
Музыка
-
Право
-
Беларуская мова
-
Французский язык
-
Немецкий язык
-
МХК
-
ОБЖ
-
Психология
-
Физкультура и спорт
-
Астрономия
-
Кыргыз тили
-
Оʻzbek tili