а) 2cos60° - tg(π/4) cos60° = 1/2, tg(π/4) = 12 * 1/2 - 1 = 1 - 1 = 0
Ответ: 0
б) sin(-420°) sin(-420°) = sin(360° - 60°) = sin(-60°) = -sin(60°) = -√3/2
Ответ: -√3/2
а) 2cos60° - tg(π/4)
cos60° = 1/2, tg(π/4) = 1
2 * 1/2 - 1 = 1 - 1 = 0
Ответ: 0
б) sin(-420°)
sin(-420°) = sin(360° - 60°) = sin(-60°) = -sin(60°) = -√3/2
Ответ: -√3/2