Рассмотрим левую часть: 4sina*sin(п/3+a)*sin(п/3-a) = 4sina*(sin(п/3)*cos(a) + cos(п/3)*sin(a)) * (sin(п/3)*cos(a) - cos(п/3)*sin(a)) = (в двух последних скобках - это произведение суммы и разности двух чисел: (a-b)(a+b)=a²-b², воспользуемся этой формулой и раскроем скобки) = 4sina*( sin² (п/3)*cos² (a) - cos² (п/3) * sin² (a) ) =
4sina*( 1/4*cos² (a) – 3/4 * sin² (a) ) = (сокращаем на 4, и воспользуемся тем что соs² = 1-sin² ) = sina*( 1 – sin² (a) - 3*sin² (a)) = sina*( 1 –4*sin² (a))
4sina*sin(п/3+a)*sin(п/3-a)=sin3a
Рассмотрим левую часть: 4sina*sin(п/3+a)*sin(п/3-a) = 4sina*(sin(п/3)*cos(a) + cos(п/3)*sin(a)) * (sin(п/3)*cos(a) - cos(п/3)*sin(a)) = (в двух последних скобках - это произведение суммы и разности двух чисел: (a-b)(a+b)=a²-b², воспользуемся этой формулой и раскроем скобки) = 4sina*( sin² (п/3)*cos² (a) - cos² (п/3) * sin² (a) ) =
4sina*( 1/4*cos² (a) – 3/4 * sin² (a) ) = (сокращаем на 4, и воспользуемся тем что соs² = 1-sin² ) = sina*( 1 – sin² (a) - 3*sin² (a)) = sina*( 1 –4*sin² (a))
Рассмотрим правую часть: sin3a= sina – 4*sin³ (a)) = sina*( 1 –4*sin² (a))
Следовательно, выражения в левой и правой частях тождественно равны.
阿迪爾汗
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom
is my mother. She has baked a delicious strawberry pie.
are my grandparents. They are riding bikes.
is our house. I can see it from here.
are my parents. My Mom’s name is Ann and my father’s name is Tom