A basic result is that the trigonometric polynomials are dense in the space of continuous functions on the unit circle, with the uniform norm ; this is a special case of the Stone–Weierstrass theorem. More concretely, for every continuous function "f" and every "ε" > 0, there exists a trigonometric polynomial "T" such that |"f"("z") − T("z")| < "ε" for all "z". Fejér's theorem states that the arithmetic means of the partial sums of the Fourier series of "f" converge uniformly to "f", provided "f" is continuous on the circle, thus giving an explicit way to find an approximating trigonometric polynomial "T".