Verified answer

Объяснение:

у=3cos(x+π/3)

y=1,5

1,5=3cos(x+π/3)

cos(x+π/3)=0,5

cos(x+π/3)=1/2

x+π/3=π/3+2πn,n∈z

x+π/3=5π/3+2πn,n∈z

x=2πn,n∈z

x=4π/3+2πn,n∈z

ответ:

х=2πn,n∈z

x=4π/3+2πn,n∈z