© 2004 Paul Dawkins
© 2004 Paul Dawkins 11
Table of Laplace Transforms Table of Laplace Transforms
(
( ) )
11{ { ( ( )) }}
f
f t t
= =
LL-- F F ss F F s( ( )
s) = =
LL{ {
f f t( ( ))
t}}
f f t( ( )
t) = =
LL--11{ {
F F ss( ( )) }}
F F s( ( )
s) = =
LL{ {
f f t( ( ))
t}}
1. 1
1. 1 11
s
s 2.2. eeat at 11
s s a
- -
a 33. . t t nn,, nn
= =
11,, 22,,3 3,,KK1 1
!!
n n
n n s
s ++ 4.4. t t ,, p > -1 p > -1
( ( ))
1 1
1 1
p p
p p s s ++
G G + +
5.
5. t t 3322
2 2 s s
p p
6.6.
1 1 2
2,, 11,, 22,,33,,
n
t n
t nn
- -
=
=
KK( (
1122))
1
1 33 55 22 11 2
2nn nn n n s s
p p +
+
× × × ×
LL- -
7.
7. sinsin
( ( ))
atat 22 aa 22s
s
+ +
aa 8.8. coscos( ( ))
at at 22 s s 22s
s
+ +
aa 9.9. t t sinsin
( ( ))
at at( (
22 22))
222 2asas s
s
+ +
aa 10.10. t t coscos( ( ))
at at( ( ))
2 2 22
2 2 2
2 22
s s aa s s aa
- - +
+
11.11. ssiinn
( ( )
aat t a) - -
at t ccooss( ( ))
aat t( ( ))
3 3
2 2 2
2 22
2 2aa s
s
+ +
aa 12.12. ssiinn( ( )
aat t a) + +
at t ccooss( ( ))
aat t( ( ))
2 2
2 2 2
2 22
2 2asas s
s
+ +
aa 13.13. ccooss
( ( )
aat t a) - -
at t ssiinn( ( ))
aat t( ( ))
( ( ))
2 2 22
2 2 2
2 22
s
s s s aa s s aa
- - +
+
14.14. ccooss( ( )
aat t a) + +
at t ssiinn( ( ))
aat t( ( ))
( ( ))
2
2 22
2 2 2
2 22
3 3 s
s s s aa s
s aa
+ + +
+
15.
15. sinsin
( (
at at b+ +
b))
( ( ) ) ( ( ))
2 2 22
ssiinn ccooss s
s b b a a bb s
s aa
+ + +
+
16.16. coscos( (
at at b+ +
b))
( ( ) ) ( ( ))
2 2 22
ccooss ssiinn s
s b b a a bb s
s aa
- - +
+
17.
17. sinhsinh
( ( ))
at at 22 aa 22s
s
- -
aa 18.18. coshcosh( ( ))
at at 22 s s 22s
s
- -
aa 19.19. eeat at sinsin
( ( ))
bt bt( ( ))
22 22b b s
s a
- -
a+ +
bb 20.20. eeat at coscos( ( ))
bt bt( ( ))
22 22s s aa s
s a a bb
- - -
- + +
21.21. eeat at sinhsinh
( ( ))
bt bt( ( ))
22 22b b s
s a
- -
a- -
bb 22.22. eeat at coshcosh( ( ))
bt bt( ( ))
22 22s s aa s
s a a bb
- - -
- - -
2233. . t t n n at eeat ,, nn
= =
11,, 22,, 33,,KK( ( ))
11!!
n n
n n s
s a
- -
a ++ 24.24. f f ct( ( ))
ct 11 F F ssc c cc
æ æ öö ç ç ÷÷
è è øø
25.
25. u t u t u cc
( ( ) ) ( = =
u t c( ))
t c- -
Heaviside Function Heaviside Function
cs cs
s s
-
ee-
26.26. d d
( ( -
t t cc- ))
Dirac Delta Function Dirac Delta Function
cs -cs
ee- 27.
27. u t f u t f t cc
( ( ) ) ( ( ))
t cc- -
ee--cscs F F ss( ( ))
28.28. u u t cc( ( )
t g) (
g t( ))
t ee--cscs LL{ { ( (
t t cc+ + )) }}
29.
29. eect ct f f t
( ( ))
t F F s( (
s cc- - ))
30.30. t t f nn f t( ( ))
t ,, nn= =
11,, 22,,3 3,,KK( ( )) - -
11 nn F F ( ( )) nn( ( ))
ss31.
31. 11 f f t
( ( ))
tt
t
( ( ))
s
s F F u u dudu
¥
òò
¥ 32.32.òò
00t t f f v( ( ))
v dvdv F F ss( ( ))
s s 33.
33.
( ( ) ) ( ( ))
0 0 t
t f f t t
- -
t t g g t t d d t tòò
F F s( ( )
s G) (
G ss( ))
34.34. f f t( ( )
t T+ +
T) ( = =
f f t( ))
t 00( ( ))
1 1
T T st st
sT sT
f
f t t dt dt
- -
-
-
--
òò
eeee
35.
35. f f t
¢¢ ( ( ))
t sF sF s( ( )
s) ( - -
f f( ))
00 36.36. f f t¢¢¢¢ ( ( ))
t s s F 22F s( ( )
s) - -
sf sf( ( )
00) - -
f f¢ ¢ ( ( ))
0037.
37. f f ( ( ))nn
( ( ))
t t s s F n n F s( ( )
s) - -
s s f n n - - 11f( ( )
00) - -
s s nn--22f f¢¢ ( ( ))
00 LL- -
sf sf ( ( n n - - 22))( ( ))
00- -
f f ( ( nn--11))( ( ))
00
© 2004 Paul Dawkins
© 2004 Paul Dawkins 22
Table Notes Table Notes
1.
1. This list is not inclusive and only contains soThis list is not inclusive and only contains some of the more commonly usedme of the more commonly used Laplace transforms and
Laplace transforms and formulas.formulas.
2.
2. Recall the definition of hyperbolic trig functRecall the definition of hyperbolic trig functions.ions.
(
( ) ) ( ( ))
ccoosshh ssiinnhh
2
2 22
t
t tt tt tt
t
t t t
-
- --
+
+ - -
=
=
ee ee= =
ee ee3.
3. Be careful when usinBe careful when using “normal” trig function vs. hyperbolic trig “normal” trig function vs. hyperbolic trig functions. g functions. TheThe only difference in the formulas is the “+ a
only difference in the formulas is the “+ a22” for the “normal” trig funct” for the “normal” trig functionsions becomes a “- a
becomes a “- a22” for the hyperbolic trig functions!” for the hyperbolic trig functions!
4.
4. Formula #4 uses the Gamma Formula #4 uses the Gamma function which is defined asfunction which is defined as
( ( ))
110 0
x x t t
t
t ¥¥ - - x x d-- dxx
G
G = = òò ee
If
Ifnn is a po is a positive integer then,sitive integer then,
( (
n n 11))
nn!!G
G + + = =
The Gamma function is
The Gamma function is an extension of the normal fan extension of the normal factorial function. actorial function. Here are aHere are a couple of quick facts for t
couple of quick facts for the Gamma functionhe Gamma function
(
( ) ) ( ( )) ( )
( ) ( ( ) ) ( ( )) ( ( )) ( ( ))
1 1 1
1 22 11
1 1 2 2 p
p p p pp
p p nn p
p p p p p p p nn
p p
p p
G
G + = + = G G
G G + + +
+ + + + + - - = = G G æ
æ öö G
G ç ç ÷÷ = = è è øø
L
L