F(x)=sin(3t+π/4)=√2/2sin(3t)+√2/2cos(3t)F( cos(ω0))=π[δ(ω-ω0)+δ(ω+ω0)]F(sin(ω0))=jπ[δ(ω+ω0)-δ(ω-ω0]F(f(x))=√2/2{π[δ(ω-ω0)+δ(ω+ω0)]}+√2/2{jπ[δ(ω+ω0)-δ(ω-ω0]}