无需计算IDTFT，判断下图所示的谱在时域对应什么样的序列？http://nos.netease.com/edu-image/C1207154BBBDEBEC7D40959111601BBE.png?imageView&thumbnail=520x520&quality=100
举一反三
- 下图所示信号，利用傅里叶变换的性质，http://nos.netease.com/edu-image/F9AC0EAE656A58C6B840B77F44F798F9.png?imageView&thumbnail=520x520&quality=100和http://nos.netease.com/edu-image/1B59D65990752182463FA8D27B1D6589.png?imageView&thumbnail=520x520&quality=100分别为( )。
- 下图描述的密码属于http://nos.netease.com/edu-image/237ACC775E85A99FC393A102E8CEA8A2-1442217414283?imageView&thumbnail=520x520&quality=100
- 如下图所示的安全邮件系统中，密钥K应该是http://nos.netease.com/edu-image/AA0121030146E1CC249F509A95EE1CC7.png?imageView&thumbnail=520x520&quality=100
- http://nos.netease.com/edu-image/D00226428A68B461C3DBE595BE8B126C-1445045240312?imageView&thumbnail=520x520&quality=100
- http://nos.netease.com/edu-image/DCA9CF6A30595C532E3CCCDE0F107952-1442111327587?imageView&thumbnail=520x520&quality=100