function dataTCO
x = [65 55 45 35 25 15 5 -5 -15 -25 -35 -45 -55]';
y=[-3.1 -3.22 -3.3 -3.32 -3.17 -3.07 -3.02 -3.02 -3.12 -3.2 -3.35 -3.37 -3.25]';
coeff=approxcos(x(end:-1:1),y(end:-1:1),4,[-55:0.1:65]);
return