Question

Solve the equation: cos 2θ = $\frac{\sqrt{5} + 1}{4}$, θ ∈[0, 2π].

Answer 1

Answer:

θ = n∏ ± (∏ /10) , n is an integer

Step-by-step explanation:

Formula used:

The solution of cosθ = cos∅ is

θ = 2n∏ ± ∅

That is,

θ = n360⁰ ± ∅

cos 2θ =(√5+1)/4 , θ ∈[0, 2π].

cos 2θ = cos 36⁰

2θ = n360⁰ ± 36⁰

θ = n180⁰ ± 18⁰

θ = n∏ ± (∏ /10) , n is an integer