write an example of a matlab code to plot a DTMF signal

% Generate a DTMF signal fs = 8000; % Sampling frequency duration = 1; % Duration of the signal t = 0:1/fs:duration-1/fs; % Time axis f1 = 697; % Frequency of the first tone f2 = 1209; % Frequency of the second tone tone1 = cos(2pif1t); % First tone tone2 = cos(2pif2t); % Second tone signal = tone1 + tone2; % DTMF signal

% Plot the DTMF signal figure; plot(t, signal); xlabel('Time (s)'); ylabel('Amplitude'); title('DTMF Signal'); grid on;