1.求f(t)的复振幅和屐开誠傅立叶級数 P90(3-5) f()=co+∑ C. COS((mOt+) °n2mf(pwm= c/T Ee-inon dt nO,T 2ET SIn nO,T 21.求f(t)的复数振幅和展开成傅立叶级数 P90 (3-5) ( ) cos( ) 1 1 = 0 +  +  = f t c c n t n n Ee dt T f t e dt T c j n t T T j n t T n T 1 2 1 2 2 2 2 ( ) 2  −  − − −   = = ] 2 2 sin [ 2 1 1      n n T E =