重邮 信号与系统考试答案 考研必备
(2)f1(k) f2(k) k k (a)(3)f1(k) f2(k) k(a)
k 1
k 1
k 1 .
k 1 .
k
(4)f1(k 1) f2(k 1) (k 1) k 1 a(5) f1(k 1) f2(k 1) (k 1)a
1.18. (1)偶、偶谐
(3)偶、偶谐奇谐(非唯一)
(5)奇偶谐
1.19 解:(1)
k
k .
k 2 .
(2)偶、奇谐 (4)奇、奇谐 (6)奇、奇谐 偶谐
UC US 2I I'
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UC RI2 2I2 I2 2I2
I2 I IC
duc'''
I2 2I2dt
'''
UC (I US 2I' I'') 2(I' US 2I'' I''')IC C
'''US 2I I' I US 2I' I'' 2I' 2US 4I'' 2I'''
整理得:
'''
2I''' 5I'' 5I' 3I 2US US US
(2)
1t
U( )d U2 1'
UC U U'
2
1''
IC CUC UC U U'
211t
I IC I2 U U' U( )d
22 UC
2I I' U( )d U US
t