Ответ:

1) cos 390⁰ = cos(360⁰ + 30⁰) = cos 30⁰ = sqrt(3)/2

2) tg(-p/4) = - tg(p/4) = -1

3) sin(-37p/6) = - sin(37p/6);

37p/6 : 2p ≈ 3

2p × 3 = 6p

37p/6 - 6p = p/6 => -sin(37p/6) = -sin(p/6) = -1/2

Объяснение: