If sin4α+4cos4β+2=4√2 sinαcosβ;α,β∈[0,π], then cos(α+β)−cos(α−β) is equal to :

2 sin A cos Acos2 A − sin2 A

If sinx + sin 2 8 4 x = 1 then cos x + 2cosx + cosx is equal to

For α,β,γ≠0. If sin−1α+sin−1β+sin−1γ=π and (α+β+γ)(α−γ+β)=3αβ, then γ equal to

If α,−π2<α<π2 is the solution of 4cosθ+5sinθ=1, then the value of tanα is

Given that sin θ = ௔௕, then cos θ is