... d2n=∞n=1n2a2n+ b2n+ c2n+ d2n14 15 -1-0 .5 0 .5 1-0.2-0.10.10.2-1-0 .5 0 .5 1-0.2-0.10.10.2Figure 28.13: The odd and even periodic extension of x(1 − x), 0 ≤ x ≤ 1.The ... the formp2y+ p1y+ p0y = µy, for a ≤ x ≤ b,α1y(a) + α2y(a) = 0, β1y(b) + β2y(b) = 0,where the pjare real and continuous and p2> 0 on [a, b], and the αj and ... convergent in the mean. For any fixed x, the sum converges to12(f(x−)+f(x+)). If f (x) is continuous and satisfies the boundary conditions, then the convergence is uniform.14 27 Thus the Fourier...