Page 93 - LAPLACE TRANSFORM

when s = – 3 ;3s = A( + ) + (Bs + C) (s + 3)

2
3(– 3) = A [(– 3) +5]

– 9 = A [14]

A = −

3s = A( + ) + (Bs + C) (s + 3)

2
3s = As + 5A + Bs + 3Bs + Cs + 3C
2

2
s : 0 = A + B ----------------- (1)

s: 3 = 3B + C --------------- (2)

Without s: 0 = 5A + 3C ----------- (3)

From expression (1): 0 = A + B

B= – A =

From expression (2) 3 = 3B + C

9 27 42 27
C = 3 – 3B = 3 – 3( ) = 3 – = –
14 14 14 14

C =

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