Question

вычислите :(sin⁡〖43°]+sin⁡〖17°〗) /(2 cos⁡〖13+3〗 sin⁡77°)=?

Answer 1

$\displaystyle\bf\\\frac{Sin43^\circ+Sin17^\circ}{2Cos13^\circ+3Sin77^\circ}=\frac{2Sin\dfrac{43^\circ+17^\circ}{2} \cdot Cos\dfrac{43^\circ-17^\circ}{2} }{2Cos13^\circ+3Sin(90^\circ-13^\circ)} =\\\\\\=\frac{2Sin30^\circ\cdot Cos13^\circ}{2Cos13^\cdot+3Cos13^\circ} =\frac{2\cdot\frac{1}{2} \cdot Cos13^\circ}{5Cos13} =\frac{1}{5} =0,2\\\\\\Otvet \ : \ 0,2$