Page 24 - LAPLACE TRANSFORM
P. 24
1x2x3x4
= 3 [ ]
(s) 4+1
= 3 [ 24 ]
( ) 5
=
( )
4 -2t
ʆ {3 t e } = 72 change s to s= (s+2)
( ) 5
=
( + )
ii) B: ʆ {4 cos 7t} = 4 [ ] (refer to table)
2
+ѡ 2
= 4 [ ]
2
+7 2
=
+
2t
ʆ {4 cos 7t e } = 4 change s to s= (s−2)
2
+7 2
= 4 ( −2)
2
( −2) + 7 2
= −
( − ) +
4 -2t
2t
ʆ {f(t)} = ʆ {3 t e + 4 e cos 7t}
= + −
( + ) ( − ) +
18
