Question

If
sin 0 + sin2 0 = 1,
show that :
cos2 0 + cos4 0 = 1.​

Answer 1

Step-by-step explanation:

Given, Sinθ + Sin2θ = 1

To prove that :- Cos2θ + Cos4θ = 0

Now, Sinθ + Sin2θ = Sin90°

θ + 2θ = 90°

3θ = 90°

θ = 30°

Hence we have to find the following :-

Cos 2×30° + Cos 4×30°

Cos 60° + Cos 120°

Cos 60° = Cos 120°=1/2

⇒1/2 - 1/2 = 0

Hence proved