"A basic result is that the response of an LTI system is given by convolution of the input and the impulse response of the system. In this chapter and the
following one we present an alternative representation for signals and LTI systems. In this chapter, the Laplace transform is introduced to represent continuous-time signals in the s-domain (s is a complex variable), and the concept of the system function for a continuous-time LTI system is described. Many useful insights into the properties of continuous-time LTI systems, as well as the study of many problems involving LTI systems, can be provided by application of the Laplace transform technique."
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GATE Answer Keys For Electronics and Communication 
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