The plane z = 0 defines the boundary between two dielectrics. For z < 0, ∈_r1 = 9, ∈"_r1 = 0, and μ₁ = μ₀. For z > 0, ∈'_r2 = 3, ∈"_r2 = 0, and μ₂ = μ₀. Let E⁺_x1 = 10 cos(ωt − 15z) V/m and find

(a) ω;

(b) (S⁺₁);

(c) (S⁻₁);

(d) (S⁺₂).