Найдите значение выражения sin 240*

Лебедев Дмитрий Сергеевич

Учитель математики

Проверено учителем

Для нахождения значения sin240sine 240 raised to the composed with power воспользуемся свойствами тригонометрических функций и формулами приведения. 1. Определение четверти Угол 240240 raised to the composed with power находится в III четверти тригонометрического круга (так как 180<240<270180 raised to the composed with power is less than 240 raised to the composed with power is less than 270 raised to the composed with power). В этой четверти значение синуса всегда отрицательное. 2. Использование формул приведения Мы можем представить 240240 raised to the composed with power двумя способами:

  • Способ через 180180 raised to the composed with power:
    sin240=sin(180+60)sine 240 raised to the composed with power equals sine open paren 180 raised to the composed with power plus 60 raised to the composed with power close paren
    Согласно формуле sin(180+α)=sinαsine open paren 180 raised to the composed with power plus alpha close paren equals negative sine alpha:
    sin(180+60)=sin60sine open paren 180 raised to the composed with power plus 60 raised to the composed with power close paren equals negative sine 60 raised to the composed with power Способ через 270270 raised to the composed with power:
    sin240=sin(27030)sine 240 raised to the composed with power equals sine open paren 270 raised to the composed with power minus 30 raised to the composed with power close paren
    Согласно формуле sin(270α)=cosαsine open paren 270 raised to the composed with power minus alpha close paren equals negative cosine alpha:
    sin(27030)=cos30sine open paren 270 raised to the composed with power minus 30 raised to the composed with power close paren equals negative cosine 30 raised to the composed with power

3. Вычисление итогового значения Используя табличные значения тригонометрических функций:

  • sin60=32sine 60 raised to the composed with power equals the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction cos30=32cosine 30 raised to the composed with power equals the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction

В обоих случаях получаем: sin240=32sine 240 raised to the composed with power equals negative the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction Ответ: 32negative the fraction with numerator the square root of 3 end-root and denominator 2 end-fraction (или примерно -0,866negative 0 comma 866). Хотите, чтобы я помог вычислить значение другой тригонометрической функции или разобрал аналогичный пример с радианами?

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