1) 24√2*cos(π/3)*(-sin(π/4)) = -24√2*(1/2)*√2/2 = -24*2/4 = -12
3) 24*(sin^2(17) - cos^2(17))/cos(34) = -24*(cos^2(17) - sin^2(17))/cos(34) = -24*cos(2*17)*cos(34) = -24
2) cosx = 1/2
x = +-π/3 + 2πk, k∈Z
наименьший положительный корень при k=0, x = π/3 = 60 градусов