Question

Sin 5п/6 cos п/6+sin п/6 cos 5п/6 решить

Answer 1

$\sin(\alpha+\beta)=\sin\alpha\cos\beta+\cos\alpha\sin\beta\\\sin\frac{5\pi}6\cos\frac\pi6+\cos\frac{5\pi}6\sin\frac\pi6=\sin\left(\frac{5\pi}6+\frac\pi6\right)=\sin\frac{6\pi}6=\sin\pi=0$