DEFINITION of unilateral Laplace transform is:\(X\left( s \RIGHT) = \mathop \smallint \nolimits_0^\infty x\left( t \right){e^{ - st}}dt\)For x(t) = e-at u(t), the Laplace transform using the above definition is obtained as:\(e^{-at}u(t)\leftrightarrow\frac{1}{s+a}\)Since e-at u(t) is a right-sided sequence, the ROC will be Re{s} > aApplication:GIVEN x(t) = e-3T u(t)\(e^{-3t}u(t)\leftrightarrow\frac{1}{s+3}\)The ROC will be: Re{s} > 3