The number of solution of cos 2 ⁡ x + cos 2 ⁡ 2 x = 2 in 0,20 is equal to

Step-by-step solution

For this to be true cos 2 ⁡ x = 1 and cos 2 ⁡ 2 x = 1 So, x = n π Since x ∈ 0,20 , n = 0 , 1 , 2 , 3 , 4 , 5 , 6