Mixed problem for the wave equation with a summable potential and nonzero initial velocity

The resolvent approach in the Fourier method, combined with Krylov’s ideas concerning convergence acceleration for Fourier series, is used to obtain a classical solution of a mixed problem for the wave equation with a summable potential, fixed ends, a zero initial position, and an initial velocity ψ(x), where ψ(x) is absolutely continuous, ψ'(x) ∈ L ₂0,1], and ψ(0) = ψ(1) = 0. In the case ψ(x) ∈ L0,1], it is shown that the series of the formal solution converges uniformly and is a weak solution of the mixed problem.