Eliminate θ between a=cos(θ-α) and b=sin(θ-β)
Solution:
(θ-α)=cos-1(a)-----(1)(θ-β)=sin-1(b)-----(2)subtractingtheequation,weget(β-α)=cos-1(a)-sin-1(b)
Hence, (β-α)=cos-1(a)-sin-1(b) where θ is eliminated.
If cos3θ = αcosθ+βcos3θ, then (α,β) =