Question

объясните пж а то с тригонометрией проблемы

Answer 1

$\frac{cos40 + cos80}{cos200} = \frac{2cos (\frac{80 + 40}{2})cos( \frac{8 0- 40}{2}) }{cos(180 + 20)} = \frac{2cos60cos20}{ - cos20} = - 2cos60 = - 2 \times \frac{1}{2} = - 1$

Answer 2

cos200 = cos(180+20) = -cos20

cos40+cos80 = 2cos60cos20

Сокращаем на cos20 и получаем = -2cos60 = -2*1/2 = -1

Ответ: -1