Значение примера: sin 3п/7 cos п/14+cos3п/7 sin п/14

Question

Значение примера: sin 3п/7 cos п/14+cos3п/7 sin п/14

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Answer 1

Sin3π/7Cosπ/14 + Cos3π/7Sinπ/14 = Sin(3π/7 + π/14) = Sinπ/2 = 1

Sin3π/8Sinπ/8 - Cos3π/8Cosπ/8 = - (Cos3π/8Cosπ/8 - Sin3π/8Sinπ/8) =
= - Cos(3π/8 + π/8) = - Cosπ/2 = 0