Вычислите sin t и cos t, если: а) t= 5пи/ 6 б) t= 5пи/4 в) t= 7пи/6 г) t= 9пи/4

Лебедев Дмитрий Сергеевич

Учитель математики

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Для заданных значений аргумента tt значения тригонометрических функций следующие: а) sint=12,cost=32sine bold t equals one-half comma cosine bold t equals negative the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction ; б) sint=22,cost=22sine bold t equals negative the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction comma cosine bold t equals negative the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction ; в) sint=12,cost=32sine bold t equals negative one-half comma cosine bold t equals negative the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction ; г) sint=22,cost=22sine bold t equals the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction comma cosine bold t equals the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction . ️ Шаг 1: Вычисление для t=5π6t equals the fraction with numerator 5 pi and denominator 6 end-fraction Угол t=5π6t equals the fraction with numerator 5 pi and denominator 6 end-fraction находится во второй четверти тригонометрического круга. Его можно представить как ππ6pi minus the fraction with numerator pi and denominator 6 end-fraction . Во второй четверти синус положителен, а косинус отрицателен: sin(5π6)=sin(ππ6)=sin(π6)=12sine open paren the fraction with numerator 5 pi and denominator 6 end-fraction close paren equals sine open paren pi minus the fraction with numerator pi and denominator 6 end-fraction close paren equals sine open paren the fraction with numerator pi and denominator 6 end-fraction close paren equals one-half cos(5π6)=cos(ππ6)=cos(π6)=32cosine open paren the fraction with numerator 5 pi and denominator 6 end-fraction close paren equals cosine open paren pi minus the fraction with numerator pi and denominator 6 end-fraction close paren equals negative cosine open paren 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 ️ Шаг 2: Вычисление для t=5π4t equals the fraction with numerator 5 pi and denominator 4 end-fraction Угол t=5π4t equals the fraction with numerator 5 pi and denominator 4 end-fraction находится в третьей четверти. Его можно представить как π+π4pi plus the fraction with numerator pi and denominator 4 end-fraction . В третьей четверти и синус, и косинус имеют отрицательные значения: sin(5π4)=sin(π+π4)=sin(π4)=22sine open paren the fraction with numerator 5 pi and denominator 4 end-fraction close paren equals sine open paren pi plus the fraction with numerator pi and denominator 4 end-fraction close paren equals negative sine open paren the fraction with numerator pi and denominator 4 end-fraction close paren equals negative the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction cos(5π4)=cos(π+π4)=cos(π4)=22cosine open paren the fraction with numerator 5 pi and denominator 4 end-fraction close paren equals cosine open paren pi plus the fraction with numerator pi and denominator 4 end-fraction close paren equals negative cosine open paren the fraction with numerator pi and denominator 4 end-fraction close paren equals negative the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction ️ Шаг 3: Вычисление для t=7π6t equals the fraction with numerator 7 pi and denominator 6 end-fraction Угол t=7π6t equals the fraction with numerator 7 pi and denominator 6 end-fraction также находится в третьей четверти. Его можно представить как π+π6pi plus the fraction with numerator pi and denominator 6 end-fraction : sin(7π6)=sin(π+π6)=sin(π6)=12sine open paren the fraction with numerator 7 pi and denominator 6 end-fraction close paren equals sine open paren pi plus the fraction with numerator pi and denominator 6 end-fraction close paren equals negative sine open paren the fraction with numerator pi and denominator 6 end-fraction close paren equals negative one-half cos(7π6)=cos(π+π6)=cos(π6)=32cosine open paren the fraction with numerator 7 pi and denominator 6 end-fraction close paren equals cosine open paren pi plus the fraction with numerator pi and denominator 6 end-fraction close paren equals negative cosine open paren 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 ️ Шаг 4: Вычисление для t=9π4t equals the fraction with numerator 9 pi and denominator 4 end-fraction Угол t=9π4t equals the fraction with numerator 9 pi and denominator 4 end-fraction превышает полный оборот ( 2π2 pi). Его можно представить как 2π+π42 pi plus the fraction with numerator pi and denominator 4 end-fraction . Этот угол находится в первой четверти, где все функции положительны: sin(9π4)=sin(2π+π4)=sin(π4)=22sine open paren the fraction with numerator 9 pi and denominator 4 end-fraction close paren equals sine open paren 2 pi plus the fraction with numerator pi and denominator 4 end-fraction close paren equals sine open paren the fraction with numerator pi and denominator 4 end-fraction close paren equals the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction cos(9π4)=cos(2π+π4)=cos(π4)=22cosine open paren the fraction with numerator 9 pi and denominator 4 end-fraction close paren equals cosine open paren 2 pi plus the fraction with numerator pi and denominator 4 end-fraction close paren equals cosine open paren the fraction with numerator pi and denominator 4 end-fraction close paren equals the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction Ответ: а) sin5π6=12,cos5π6=32sine the fraction with numerator 5 bold pi and denominator 6 end-fraction equals one-half comma cosine the fraction with numerator 5 bold pi and denominator 6 end-fraction equals negative the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction б) sin5π4=22,cos5π4=22sine the fraction with numerator 5 bold pi and denominator 4 end-fraction equals negative the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction comma cosine the fraction with numerator 5 bold pi and denominator 4 end-fraction equals negative the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction в) sin7π6=12,cos7π6=32sine the fraction with numerator 7 bold pi and denominator 6 end-fraction equals negative one-half comma cosine the fraction with numerator 7 bold pi and denominator 6 end-fraction equals negative the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction г) sin9π4=22,cos9π4=22sine the fraction with numerator 9 bold pi and denominator 4 end-fraction equals the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction comma cosine the fraction with numerator 9 bold pi and denominator 4 end-fraction equals the fraction with numerator the square root of 2 end-root and denominator 2 end-fraction Нужно ли вам также рассчитать значения тангенса и котангенса для этих углов?

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