+0  
 
+2
110
1
avatar+293 

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 = 

 Nov 20, 2020
 #1
avatar+116126 
+2

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

 

 

cool cool cool

 Nov 20, 2020

74 Online Users

avatar
avatar
avatar
avatar
avatar
avatar