R, K, n/2 Pi , {n, 1

(* stdunia potencjału z deltą Diraca w środku *)
R = 10;
sol = TableFindRootK /Tan[K] ⩵ -R, K, n /2 Pi, {n, 1, 10, 2} // Union;
psi1[x_, K_] = 5 Whichx < 0, Sin[K (x +1)], x > 0, -Sin[K (x -1)];
psi2[x_, K_] = 5 Whichx < 0, Sin[K (x +1)], x > 0, Sin[K (x -1)];
rys1 = PlotTableK ^ 2, psi2[x, K]+K ^ 2, K, Pi, 5 Pi, Pi,
{x, -1, 1}, Axes → None, PlotStyle → RGBColor[0, 0, 1];
rys2 = PlotTableK ^ 2 /. sol[[n]], psi1[x, K]+K ^ 2 /. sol[[n]], n, 1, Lengthsol,
{x, -1, 1}, Axes → None, PlotStyle → RGBColor[1, 0, 0];
xmax = 280;
rys3 = GraphicsLine[{{-1, 0}, {-1, xmax }}], Line[{{1, 0}, {1, xmax }}],
Line[{{-1, 0}, {1, 0}}], Dashing[0.02 {1, 1}], Line[{{0, 0}, {0, xmax }}];
Showrys1, rys2, rys3, AspectRatio→ 2