If [x] denotes the greatest integer ≤ x, then the system of linear equations [sin θ]x + [–cosθ]y = 0, [cot θ]x + y = 0
(1) has a unique solution if θ ∈(π/2, 2π/3) and have infinitely many solutions if θ ∈(π, 7π/6)
(2) have infinitely many solutions if θ ∈(π/2, 2π/3) and has a unique solution if θ ∈(π ,7π/6)
(3) have infinitely many solutions if θ ∈(π/2, 2π/3) ∪ (π,7π/6)
(4) has a unique solution if θ ∈(π/2, 2π/3) ∪ (π,7π/6)