1)sin(5x-пи/6)=1/2 2)соs(x/4-пи/6)=-корень 3/2 3)tg(3x+пи/4)=1/корень 3

Лебедев Дмитрий Сергеевич

Учитель математики

Проверено учителем

Ниже представлено подробное решение трех тригонометрических уравнений. 1) sin(5xπ6)=12sine open paren 5 x minus the fraction with numerator pi and denominator 6 end-fraction close paren equals one-half Для уравнения вида sin(t)=asine t equals a используется общая формула: t=(-1)karcsin(a)+πkt equals open paren negative 1 close paren to the k-th power arc sine a plus pi k.

  1. Запишем общее решение для аргумента:
    5xπ6=(-1)karcsin(12)+πk,kZ5 x minus the fraction with numerator pi and denominator 6 end-fraction equals open paren negative 1 close paren to the k-th power arc sine one-half plus pi k comma space k is an element of the integers Вычислим арксинус: arcsin(1/2)=π6arc sine open paren 1 / 2 close paren equals the fraction with numerator pi and denominator 6 end-fraction .
    5xπ6=(-1)kπ6+πk5 x minus the fraction with numerator pi and denominator 6 end-fraction equals open paren negative 1 close paren to the k-th power the fraction with numerator pi and denominator 6 end-fraction plus pi k Перенесем π6negative the fraction with numerator pi and denominator 6 end-fraction в правую часть:
    5x=(-1)kπ6+π6+πk5 x equals open paren negative 1 close paren to the k-th power the fraction with numerator pi and denominator 6 end-fraction plus the fraction with numerator pi and denominator 6 end-fraction plus pi k Разделим обе части на 5:
    Ответ: x=(-1)kπ30+π30+πk5,kZx equals the fraction with numerator open paren negative 1 close paren to the k-th power pi and denominator 30 end-fraction plus the fraction with numerator pi and denominator 30 end-fraction plus the fraction with numerator pi k and denominator 5 end-fraction comma space k is an element of the integers

2) cos(x4π6)=32cosine open paren x over 4 end-fraction minus the fraction with numerator pi and denominator 6 end-fraction close paren equals negative the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction Для уравнения вида cos(t)=acosine t equals a используется формула: t=±arccos(a)+2πkt equals plus or minus arc cosine a plus 2 pi k.

  1. Запишем выражение для аргумента:
    x4π6=±arccos(32)+2πk,kZx over 4 end-fraction minus the fraction with numerator pi and denominator 6 end-fraction equals plus or minus arc cosine open paren negative the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction close paren plus 2 pi k comma space k is an element of the integers Вычислим арккосинус: arccos(a)=πarccos(a)arc cosine negative a equals pi minus arc cosine a.
    arccos(32)=ππ6=5π6arc cosine open paren negative the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction close paren equals pi minus the fraction with numerator pi and denominator 6 end-fraction equals the fraction with numerator 5 pi and denominator 6 end-fraction .
    x4π6=±5π6+2πkx over 4 end-fraction minus the fraction with numerator pi and denominator 6 end-fraction equals plus or minus the fraction with numerator 5 pi and denominator 6 end-fraction plus 2 pi k Перенесем π6negative the fraction with numerator pi and denominator 6 end-fraction в правую часть:
    x4=π6±5π6+2πkx over 4 end-fraction equals the fraction with numerator pi and denominator 6 end-fraction plus or minus the fraction with numerator 5 pi and denominator 6 end-fraction plus 2 pi k Умножим все уравнение на 4:
    x=4π6±20π6+8πkx equals the fraction with numerator 4 pi and denominator 6 end-fraction plus or minus the fraction with numerator 20 pi and denominator 6 end-fraction plus 8 pi k
    x=2π3±10π3+8πkx equals the fraction with numerator 2 pi and denominator 3 end-fraction plus or minus the fraction with numerator 10 pi and denominator 3 end-fraction plus 8 pi k Распишем два случая:
    • x1=2π+10π3+8πk=4π+8πkx sub 1 equals the fraction with numerator 2 pi plus 10 pi and denominator 3 end-fraction plus 8 pi k equals 4 pi plus 8 pi k x2=2π10π3+8πk=8π3+8πkx sub 2 equals the fraction with numerator 2 pi minus 10 pi and denominator 3 end-fraction plus 8 pi k equals negative the fraction with numerator 8 pi and denominator 3 end-fraction plus 8 pi k

Ответ: x=4π+8πk;x=8π3+8πk,kZx equals 4 pi plus 8 pi k ; space x equals negative the fraction with numerator 8 pi and denominator 3 end-fraction plus 8 pi k comma space k is an element of the integers 3) tg(3x+π4)=13tg open paren 3 x plus the fraction with numerator pi and denominator 4 end-fraction close paren equals the fraction with numerator 1 and denominator the square root of 3 end-root end-fraction Для уравнения вида tg(t)=atg open paren t close paren equals a используется формула: t=arctg(a)+πkt equals arctg open paren a close paren plus pi k.

  1. Запишем выражение для аргумента:
    3x+π4=arctg(13)+πk,kZ3 x plus the fraction with numerator pi and denominator 4 end-fraction equals arctg open paren the fraction with numerator 1 and denominator the square root of 3 end-root end-fraction close paren plus pi k comma space k is an element of the integers Вычислим арктангенс: arctg(1/3)=π6arctg open paren 1 / the square root of 3 end-root close paren equals the fraction with numerator pi and denominator 6 end-fraction .
    3x+π4=π6+πk3 x plus the fraction with numerator pi and denominator 4 end-fraction equals the fraction with numerator pi and denominator 6 end-fraction plus pi k Перенесем π4the fraction with numerator pi and denominator 4 end-fraction в правую часть:
    3x=π6π4+πk3 x equals the fraction with numerator pi and denominator 6 end-fraction minus the fraction with numerator pi and denominator 4 end-fraction plus pi k
    3x=2π3π12+πk3 x equals the fraction with numerator 2 pi minus 3 pi and denominator 12 end-fraction plus pi k
    3x=π12+πk3 x equals negative the fraction with numerator pi and denominator 12 end-fraction plus pi k Разделим обе части на 3:
    Ответ: x=π36+πk3,kZx equals negative the fraction with numerator pi and denominator 36 end-fraction plus the fraction with numerator pi k and denominator 3 end-fraction comma space k is an element of the integers

Могу помочь с решением других систем уравнений или задач по тригонометрии, если это необходимо.

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