function res = spline_last(a, b, n, X)
    h = (b - a)/(n-1);
    spline_coeffs = spline(X);
    inter = a : h : b;
    original_y = zeros(1, 100);
    spline_y = zeros(1, 100);
    z = 1;

    h = (b - a) / (100*(n-1));
    line = 1;
    k = 3;
    curr_iter = inter(2);
    for i = a : h : b
        original_y(z) = func(i);
        if (i > curr_iter && line < n-1)
            %disp(i);
            line++;
            curr_iter = inter(k);
            k++;
        endif
        spline_y(z) = polyval(spline_coeffs(line, :), i);
        z++;
    endfor
    res = max(abs(spline_y - original_y));
endfunction