Question

$Вычислите: 2sin240 + cos135 -tg120$
пожалуйста

Answer 1

sin(240°) = sin(180°+60°) = -sin(60°) = -(√3)/2.
cos(135°) = cos(180° - 45°) = -cos(45°) = -(√2)/2.
tg(120°) = tg(180° - 60°) = tg(-60°) = -tg(60°) = -√3,
Поэтому
2sin(240°) + cos(135°) - tg(120°) = 2*(-(√3)/2) - ((√2)/2) - (-√3) = 
= -(√3) - ((√2)/2) + √3 = -(√2)/2.