Dual Tone Multi Frequency with Waveforms

clc;
clear all;
close all;
fs=8000;
f1=770+/fs;
f2=1209/fs;
n=1:205;
x1=sin(2*pi*f1*n);
x2=sin(2*pi*f2*n);
x=x1+x2;
y=fft(x,205);
K=1:50;
z(K)=y(K);
stem(K,abs(z));
xlabel('k');
ylabel('amplitude');
title('DTMF signal');