Page 226 - Schaum's Outline of Theory and Problems of Signals and Systems
P. 226

CHAP.  51        FOURIER ANALYSIS OF TIME SIGNALS AND SYSTEMS






























                                                      (6)
               Fig. 5-1  (a) Nonperiodic signal x(r); (b) periodic signal formed by periodic extension of  x(r ).



             can be rewritten as






                 Let  us define  X(w) as





             Then from  Eq. (5.246) the complex Fourier coefficients c,  can be  expressed as






             Substituting Eq. (5.26) into Eq. (5.231, we  have










             As  To -+ m,  o, = 27r/T,  becomes  infinitesimal  (w, - 0).  Thus,  let  w,, = Aw.  Then
             Eq. (5.27) becomes
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