% M-file names must start with an alphabetic character,
%   may contain any alphanumeric characters or underscores

clear;  % Clear variables and functions from memory.
clc;    % Clear command window.


% 1.2 (c)
% x(t) = exp(-t) * cos(pi*t/4);
% delta_t = 0.1, 1, 2, 3
t = 0:.618:20;                       % Assign variable t as a vector with equally spaced elements.
x = exp(-t) .* cos(pi*t/4);         % Compute exp(-t) * cos(pi*t/4) for each element in vector t, as a result, x will become a vector as well.
plot(t, x, 'LineWidth', 1.5);       % Plot vector x versus vector t, LineWidth=1.5
xlabel('Time (sec)');               % Adds text beside the X-axis on the current axis.
ylabel('x(t)');                     % Adds text beside the Y-axis on the current axis.
title('1.2 (c)');                   % Set Graph title.
