Question

Срочно!!!

Спростити вираз:

Answer 1

Ответ:

1

$2 \sin( 5\alpha ) \cos(5 \alpha ) = \sin( 2 \times 5\alpha ) = \sin( 10\alpha )$

2

$\cos {}^{2} ( 2\beta ) - \sin {}^{2} ( 2\beta ) = \cos(2 \times 2 \beta ) = \cos( 4\beta )$

3

$\frac{2tg20^{\circ} }{1 - tg {}^{2} 20^{\circ} } = tg(2 \times 20^{\circ} ) = tg(40^{\circ} )$