% Signal (a)
% n_a = 0:12;
% x_a = zeros(size(n_a));
% x_a(n_a == 5) = 1;
% x_a(n_a == 8) = -2;
% x_a(n_a == 11) = 6;
% figure;
% stem(n_a, x_a);
% xlabel('n');
% ylabel('Amplitude');
% title('\delta(n-5) - 2\delta(n-8) + 6\delta(n-11)');
% grid on;

% % Signal (b)
% n_b = 0:15;
% x_b = zeros(size(n_b));
% x_b(n_b >= 3) = 1;
% x_b(n_b >= 8) = x_b(n_b >= 8) - 2;
% x_b(n_b >= 12) = x_b(n_b >= 12) + 1;
% figure;
% stem(n_b, x_b);
% xlabel('n');
% clc;
% ylabel('Amplitude');
% title('u(n-3) - 2u(n-8) + u(n-12)');
% grid on;

% % Signal (c)
% n_c = 0:20;
% x_c = n_c .* (n_c >= 0);
% figure;
% stem(n_c, x_c);
% xlabel('n');
% ylabel('Amplitude');
% title('nu(n)');
% grid on;
% 
% % Signal (d)
% n_d = 0:10;
% x_d = n_d.^2 .* (n_d >= 0);
% figure;
% stem(n_d, x_d);
% xlabel('n');
% ylabel('Amplitude');
% title('n^2u(n)');
% grid on;
% 
% % Signal (e)
n_e = 0:30;
x_e = 3 .* (n_e - 3).^2 .* exp(-0.3 * n_e) .* sin(2 * n_e / 3) .* (n_e >= 0);
figure;
stem(n_e, x_e);
xlabel('n');
ylabel('Amplitude');
title('3(n-3)^2 e^{-0.3n} sin(2n/3)u(n)');
grid on;