We shall first consider values of θ between 0 and 2π sin θ = 21 = - sin 6π = sin (π+6π) or sin (2π – π/6) ∴ θ = 7π/6 ; 11π/6 tan θ = 1/3 = tan (π/6) or tan (π + π/6) ∴ θ = π/6 , 7π/6 The value of θ which satisfies both the equations is 7π/6 Hence the general value of θ is 2nπ + 7π/6 where n ∊ I