(a) Find the exponential Fourier series for the signal in Fig. P6.3-9a. (b) Using the results in part (a), find the Fourier series for the signal (/) in Fig. P6.3-9b, which is a time-shifted version of the signal x(t). Using the results in part (a), find the Fourier series for the signal x(1) in Fig. P6.3-9c. which is a time-scaled version of the signal x(t). - 12 8 -12 (a) -8 x(1) x(1) (b) (c) 4 +0 x(1) ^^^^^^^^^ 4 00 8 12 8 12