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Find the general solution of the equation (√3 – 1) cos θ + (√3 + 1) sin θ = 2[Hint: Put √3 – 1 = r sin α, √3 + 1 = r cos α which gives tan α = tan((π/4) – (π/6)) α = π/12] |
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Answer» Let, r sinα = √3 – 1 and r cosα = √3 + 1 Therefore, r = √{(√3 – 1)2 + (√3 + 1)2} = √8 = 2√2 And, tan α = (√3 – 1) / (√3 + 1) Therefore, r(sinα cos θ + cosα sin θ) = 2 ⇒ r sin (θ+α) = 2 ⇒ sin (θ+α) = 1/√2 ⇒ sin (θ+α) = sin (π/4) ⇒ θ+α = nπ + (– 1)n (π/4), n ∈ Z ⇒ θ = nπ + (– 1)n (π/4) – (π/12), n ∈ Z |
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