1) 2*sin(x-π/6)=-1 |÷2
sin(x-π/6)=-1/2
x-π/6=7π/6+2πn x₁=8π/6+2πn=4π/3+2πn
x-π/6=-π/6+2πn x₂=2πn.
2) 2*sin(4x)+√3=0
2*sin(4x)=-√3 |÷2
sin(4x)=-√3/2
4x=4π/3+2πn |÷4 x₁=π/3+πn/2.
4x=5π/3+2πn |÷4 x₂=5π/12+πn/2.
3) 2*cos(3x)+√3=0
2*cos(3x)=-√3 |÷2
cos(3x)=-√3/2
3x=5π/6+2πn |÷3 x₁=5π/18+2πn/3
3x=7π/3+2nn |÷3 x₂=7x/18+2πn/3.
У(3) = -2*3+3 = -6+3 = -3.
ответ : -3 .
cosacosb-sinasinb+sinasinb=cosacosb