Try this:
[pxx1,f1] = pwelch(y1,512,66.7,[],1000);
[pxx2,f2] = pwelch(y2,512,66.7,[],1000);
figure(1);
semilogx(f1,pxx1);xlabel('Frequency(Hz)');title('2*pi*50*t');
figure(2);
semilogx(f2,pxx2);xlabel('Frequency(Hz)');title('2*pi*250*t');
You will see each signal's frequency domain plot, which has peaks at 50 and 250 Hz respectively.
Best Answer