Domain of f(g(x)) is R ∵ 2 - cosx - cos2x ≥ 0 (cos x + 2)(cosx - 1) ≤ 0 ⇒ - 2 ≤ cos x ≤ 1 x ∈ R Domain of g(f(x)) is [-2, 1] ∵cos(√2−x−x2) 2−x−x2≥0 Domain of f(g(x)2) is R ∵ 2 - cos2x - cos4x ≥ 0 (cos2x + 2)(cos2x - 1) ≤ 0 -1 ≤ cos x ≤ 1 x ∈ R Domain of g(f3(x)) is Domain of g(f(x) i.e., [-2, 1]