x(t)X(s)Region of Convergenceδ(t)1All s∈Cu(t)s1Re(s)>0e−atu(t)s+a1Re(s)>−aeatu(t)s−a1Re(s)>atnu(t)sn+1n!Re(s)>0cos(ω0t)u(t)s2+ω02sRe(s)>0sin(ω0t)u(t)s2+ω02ω0Re(s)>0e−atcos(ωt)u(t)(s+a)2+ω2s+aRe(s)>−ae−atsin(ωt)u(t)(s+a)2+ω2ωRe(s)>−aδ(t−T)e−sTAll s∈Cu(−t)−s1Re(s)<0 All of these have a u(t) factor because we assume casual signals