Question

Спростіть вираз (cos10x)/(sin5x+cos5x)

Answer 1

Смотри............................

Answer 2

$\displaystyle\bf\\\frac{Cos10x}{Sin5x+Cos5x} =\frac{Cos^{2} 5x-Sin^{2}5x }{Sin5x+Cos5x} =\\\\\\=\frac{(Cos5x-Sin5x)\cdot(Cos5x+Sin5x)}{Sin5x+Cos5x}=Cos5x-Sin5x$