Investigating the Degree of Approximation of Fourier Series Through Product Means

In this paper, we have established a theorem concerning the degree of approximation of functions $f \in Lip\alpha$ by means of the product summability method $(E.1)(N.p.q)$ applied to the Fourier series associated with a function. The result offers new insights into the convergence behavior and approximation properties of such summation techniques within the Lipschitz class, highlighting the effectiveness of product summability in Fourier analysis.