1) решите уравнения 1)tg(2x-π/6)=1 2)ctg(x/2+π/8)=√32) найдите решения,лежащие в указанном промежутке, и запишите их в градусах:2sin^2( 2x)+sinx=1

Лебедев Дмитрий Сергеевич

Учитель математики

Проверено учителем

Для решения тригонометрических уравнений воспользуемся стандартными формулами и методами подстановки. Поскольку для третьего уравнения промежуток не указан в тексте, решение будет представлено в общем виде с последующим переводом в градусы. ️ Шаг 1: Решение уравнения с тангенсом Уравнение имеет вид tan(2xπ6)=1tangent open paren 2 x minus the fraction with numerator pi and denominator 6 end-fraction close paren equals 1 . Используем общую формулу tanα=1α=π4+πktangent alpha equals 1 implies alpha equals the fraction with numerator pi and denominator 4 end-fraction plus pi k : 2xπ6=π4+πk2 x minus the fraction with numerator pi and denominator 6 end-fraction equals the fraction with numerator pi and denominator 4 end-fraction plus pi k 2x=π4+π6+πk2 x equals the fraction with numerator pi and denominator 4 end-fraction plus the fraction with numerator pi and denominator 6 end-fraction plus pi k Приведем к общему знаменателю: π4+π6=3π+2π12=5π12the fraction with numerator pi and denominator 4 end-fraction plus the fraction with numerator pi and denominator 6 end-fraction equals the fraction with numerator 3 pi plus 2 pi and denominator 12 end-fraction equals the fraction with numerator 5 pi and denominator 12 end-fraction . 2x=5π12+πkx=5π24+πk2,kZ2 x equals the fraction with numerator 5 pi and denominator 12 end-fraction plus pi k implies x equals the fraction with numerator 5 pi and denominator 24 end-fraction plus the fraction with numerator pi k and denominator 2 end-fraction comma k is an element of the integers ️ Шаг 2: Решение уравнения с котангенсом Уравнение имеет вид cot(x2+π8)=3cotangent open paren x over 2 end-fraction plus the fraction with numerator pi and denominator 8 end-fraction close paren equals the square root of 3 end-root . Используем формулу cotα=3α=π6+πkcotangent alpha equals the square root of 3 end-root implies alpha equals the fraction with numerator pi and denominator 6 end-fraction plus pi k : x2+π8=π6+πkx over 2 end-fraction plus the fraction with numerator pi and denominator 8 end-fraction equals the fraction with numerator pi and denominator 6 end-fraction plus pi k x2=π6π8+πkx over 2 end-fraction equals the fraction with numerator pi and denominator 6 end-fraction minus the fraction with numerator pi and denominator 8 end-fraction plus pi k Приведем к общему знаменателю: π6π8=4π3π24=π24the fraction with numerator pi and denominator 6 end-fraction minus the fraction with numerator pi and denominator 8 end-fraction equals the fraction with numerator 4 pi minus 3 pi and denominator 24 end-fraction equals the fraction with numerator pi and denominator 24 end-fraction . x2=π24+πkx=π12+2πk,kZx over 2 end-fraction equals the fraction with numerator pi and denominator 24 end-fraction plus pi k implies x equals the fraction with numerator pi and denominator 12 end-fraction plus 2 pi k comma k is an element of the integers ️ Шаг 3: Решение уравнения 2sin2(2x)+sin(x)=12 sine squared 2 x plus sine x equals 1 Данное уравнение приводится к виду 8sin4x8sin2xsinx+1=08 the fourth power of sine x minus 8 sine squared x minus sine x plus 1 equals 0 через формулу двойного угла. Заметим, что sinx=1sine x equals 1 является корнем: 8(1)48(1)21+1=08 open paren 1 close paren to the fourth power minus 8 open paren 1 close paren squared minus 1 plus 1 equals 0. Для sinx=1sine x equals 1: x=90+360nx equals 90 raised to the composed with power plus 360 raised to the composed with power n. Также уравнение можно преобразовать как 12sin2(2x)=sinxcos(4x)=sinx1 minus 2 sine squared 2 x equals sine x implies cosine 4 x equals sine x. Решая cos(4x)=cos(90x)cosine 4 x equals cosine open paren 90 raised to the composed with power minus x close paren, получаем:

  1. 4x=90x+360k5x=90+360kx=18+72k4 x equals 90 raised to the composed with power minus x plus 360 raised to the composed with power k implies 5 x equals 90 raised to the composed with power plus 360 raised to the composed with power k implies x equals 18 raised to the composed with power plus 72 raised to the composed with power k. 4x=(90x)+360k3x=-90+360kx=-30+120k4 x equals negative open paren 90 raised to the composed with power minus x close paren plus 360 raised to the composed with power k implies 3 x equals negative 90 raised to the composed with power plus 360 raised to the composed with power k implies x equals negative 30 raised to the composed with power plus 120 raised to the composed with power k.

Ответ:

  1. x=5π24+πk2,kZx equals the fraction with numerator 5 pi and denominator 24 end-fraction plus the fraction with numerator pi k and denominator 2 end-fraction comma k is an element of the integers x=π12+2πk,kZx equals the fraction with numerator pi and denominator 12 end-fraction plus 2 pi k comma k is an element of the integers x=18+72kx equals 18 raised to the composed with power plus 72 raised to the composed with power k и x=-30+120k,kZx equals negative 30 raised to the composed with power plus 120 raised to the composed with power k comma k is an element of the integers

Уточните, пожалуйста, границы промежутка для третьего уравнения, чтобы я мог выбрать конкретные значения корней в градусах.

Форма ответа

Ваш аватар