A sinusoidal signal y(t) in one period T=12 s is sampled into 11 data points (ti, yi) as listed in the table below: i 1 4 5 6 7 8 7.5 0.0 1.0 23 2.0 7.2 7.0 2.5 4.5 3.5 7.5 6.0 8.9 9 10 10.0 11.0 8.9 7.9 12.0 7.0 yi 7.6 6.5 7.2 9.1 (a) If the signal is expressed as y(t)=A+B.cos(60t-1.07), where 0o=21/T and A and B are coefficients. Determine the values of A and B using linear least-squares regression. (b) If the signal is expressed as y(t)=A+B-cos(0ot)+C+sin(not), where 00=2rt/T and A, B and Care coefficients. Answer the following questions: (i) By the transformation of variables u=cos(@ot) and v=sin(not), the signal is expressed as y(u, V)=A+Bu+Cv where the coefficients A, B and C can be determined by linear least-squares regression. Show the procedure in determining A, B and C using the fitting method of linear least-squares regression. (ii) Based on the fitting method as developed in (i), find the values of A, B and C, respectively