clear all, close all, clc;
t=(0:2:10)';
y=[1 1.6 1.4 0.6 0.2 0.8]';
A=[ones(size(t)) sin(2*pi*t/12) cos(2*pi*t/12)]
c=A\y;

kortT=0:0.05:10;
kortY=c(1)+c(2)*sin(2*pi*kortT/12)+c(3)*cos(2*pi*kortT/12);

plot(t,y,'*')
hold on
plot(kortT, kortY)