Chapter 9 6/24/2019 9
21 确定下列时间函数的拉普拉斯变换,收敛域及零极点图: (a) )()()(32tuetuetxtt (b))()5(sin)()(54tutetuetxtt (c))()()(32tuetuetxtt (d)ttetx2)( (g)x(t)= (i))()()(tuttx 解: (a) 65523121)()(2 sssssdtetxsXst右边序列收敛域为Re{s}>-2 本本次次作作业业答答案案由由于于时时间间仓仓促促可可能能有有误误,,请请大大家家小小心心甄甄别别
有有问问题题请请致致邮邮 gg__bbzzhhoouu@@ssttuu
eedduu
ccnn 1,10t 0,其余 t (b) 200901470155)5(541)(23222ssssssssX右边序列收敛域为Re{s}>-4 (c)65523121)(2ssssssX-- 左边序列收敛域为 Re{s}2 (d)整个s 平面 (Re{s}=3 在收敛域内) 2
(a)Re{s}>2 (b)Re{s}>-2 (c)Re{s}