Published by:
CGP EDU Academic Team
Published on: August 13, 2026
If cos2 θ + 3 cos θ = 0, then
A
θ = 2n π ± α where α = 
B
θ = 2n π ± α where 
C
θ = 2n π ± α where α = 
D
θ = 2n π ± α where α = 
Text Solution
Verified by ExpertsThe correct answer is:
A
cos 2 θ + 3 cos θ = 0 ⇒ 2 cos 2 θ + 3 cos θ – 1 = 0 ⇒ cos θ = 
= 
As –1 ≤ cos θ ≤ 1 ∴ cos θ = 
only
⇒ θ = 2n π ± α where cos α = 
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