Page 47 - LAPLACE TRANSFORM
P. 47

SOLUTION




                                    s + 10          s  + 10
                         F
                       1.  (s ) =             =
                                     4 −
                                                  s
                                (s 2  − s  12 )  ( +  2 )( −  ) 6
                                                        s
                                                   s + 10
                                              =
                                                     )( −
                                                ( +  2 s   ) 6
                                                 s


                                             =        +             @          +     
                                               (  +2)  (  −6)       (  −  )  (  +  )



                       multiply each side with denominator;










                                            s + 10 = A (s − 6) + B (s + 2)



                       when (s + 2) = 0

                              s= −2;        s + 10 = A (s − 6) + B (s + 2)

                                            −2 + 10 = A (−2 − 6) + B (−2 + 2)

                                                          8 = A (−8) + 0

                                                          
                                                          =   = −1
                                                       −  


                       when (s − 6) = 0

                              s= 6;

                                            s + 10 = A (s − 6) + B (s + 2)

                                            6 + 10 = A (6 − 6) + B (6 + 2)

                                                    16 = 0 + B (8)

                                                         
                                                       =   =   
                                                        




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