Use an Addition or Subtraction Formula to simplify the equation.
cos(𝜃) cos(2𝜃) + sin(𝜃) sin(2𝜃) = 1/2
Find all solutions in the interval [0, 2𝜋). (Enter your answers as a comma-separated list.) 𝜃 =
Not as difficult as it seems.....we can use an identity to simplify the given expression as :
cos ( 2 θ - θ) = 1/2
cos θ = 1/2
And this happens at 60° = pi/3 rads = θ
And at 300° = 5pi/3 rads = θ
θ = pi/3 , 5pi/3
+293 
