对以下DTFT，不计算其IDTFT，直接确定哪个的IDTFT是奇序列？奇序列是_________[img=418x119]1802d455f908b6a.png[/img]

对以下DTFT，不计算其IDTFT，直接确定哪个的IDTFT是奇序列？‌奇序列是_________‌​[img=418x119]1802d44f83efa4c.png[/img]‌

计算下列函数的IDTFT。[tex=9.286x2.643]HvfGi/JM4pFOEZE3Sf+DQuBWA8h603brgIcYxGO5giLbrmmX1ksD+H4CcgyokNrttTUZ9vuU78Qd/D0R4i/glDOU7AsgUu8gR0DXEJ17tFGr12w9jy4A5YJvN0Hj54xtmPJ8wha7I7T+yNjeOWtacwGSKDzJm7cZD++2OksiMU0ZT3e5zdgr8SlLDhsn1KAq[/tex]

计算下列函数的IDTFT。[tex=12.286x3.0]sa8lrymBoJOGvcbm07nWOMtazLB6w5hBhzXCYDbBLm1Twzu/adg64HQoR/7BaCvFHRhAXldNViEcn6jWS0o9/iUp9fxylIIi+yLTLEqBlWxW86xJq74QcMkpis1twLlFFOG2ZqNsR4lENL1OndQvulqYRXI4VzF4MqLe/Tc8BDPKoyLBGP5wxkIxeM4fAXbSWGS+SVavh3q6X4HedBk3KegmFbFa5YQDJANT7mOBcgs=[/tex]

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