Here we consider a uniform string of length 1, 0 < x < 1, with constant tension and density (c = 1). Initial shape is f(x) = cos(4 Pi x)/100, and the initial velocity is g(x) = (x - 1/2)^2.  Below we animate the solution to the wave equation (no external forces). Only the first 20 terms in the infinite series solution are used.