matlab assignment
Laplace_Table(4).pdf
Table of Laplace Transforms ( ) ( ){ }1f t F s−= L ( ) ( ){ }F s f t= L ( ) ( ){ }1f t F s−= L ( ) ( ){ }F s f t= L 1. 1
1 s
2. a te 1
s a−
3. , 1, 2, 3,nt n = … 1 !
n n
s + 4. pt , p > -1
( ) 1
1 p
p s +
Γ +
5. t 3 22s
π 6.
1 2 , 1, 2, 3,nt n− = …
( ) 1 2
1 3 5 2 1 2 nn
n s
π +
⋅ ⋅ −L
7. ( )sin at 2 2 a
s a+ 8. ( )cos at 2 2
s s a+
9. ( )sint at ( )22 2 2as
s a+ 10. ( )cost at ( )
2 2
22 2
s a
s a
−
+
11. ( ) ( )sin cosat at at− ( ) 3
22 2
2a
s a+ 12. ( ) ( )sin cosat at at+ ( )
2
22 2
2as
s a+
13. ( ) ( )cos sinat at at− ( )
( )
2 2
22 2
s s a
s a
−
+ 14. ( ) ( )cos sinat at at+
( ) ( )
2 2
22 2
3s s a
s a
+
+
15. ( )sin at b+ ( ) ( ) 2 2
sin coss b a b s a
+ +
16. ( )cos at b+ ( ) ( )2 2 cos sins b a b
s a − +
17. ( )sinh at 2 2 a
s a− 18. ( )cosh at 2 2
s s a−
19. ( )sinat bte ( )2 2 b
s a b− + 20. ( )cosat bte ( )2 2
s a s a b
−
− +
21. ( )sinhat bte ( )2 2 b
s a b− − 22. ( )coshat bte ( )2 2
s a s a b
−
− −
23. , 1, 2, 3,n att n =e … ( ) 1 !
n n
s a +
− 24. ( )f ct 1 sF
c c
25. ( ) ( )cu t u t c= − Heaviside Function
cs
s
−e 26. ( )t cδ −
Dirac Delta Function cs−e
27. ( ) ( )cu t f t c− ( )cs F s−e 28. ( ) ( )cu t g t ( ){ }cs g t c− +e L 29. ( )ct f te ( )F s c− 30. ( ) , 1, 2, 3,nt f t n = … ( ) ( ) ( )1 n nF s−
31. ( )1 f t t
( ) s
F u du ∞
∫ 32. ( )0 t
f v dv∫ ( )F s s
33. ( ) ( ) 0
t f t g dτ τ τ−∫ ( ) ( )F s G s 34. ( ) ( )f t T f t+ =
( ) 0
1
T st
sT
f t dt−
−− ∫ e
e
35. ( )f t′ ( ) ( )0sF s f− 36. ( )f t′′ ( ) ( ) ( )2 0 0s F s sf f ′− − 37. ( ) ( )nf t ( ) ( ) ( ) ( ) ( ) ( ) ( )2 11 20 0 0 0n nn n ns F s s f s f sf f− −− − ′− − − −L
Table Notes 1. This list is not a complete listing of Laplace transforms and only contains some of
the more commonly used Laplace transforms and formulas.
2. Recall the definition of hyperbolic functions.
( ) ( )cosh sinh 2 2
t t t t
t t − −+ −
= = e e e e
3. Be careful when using “normal” trig function vs. hyperbolic functions. The only
difference in the formulas is the “+ a2” for the “normal” trig functions becomes a “- a2” for the hyperbolic functions!
4. Formula #4 uses the Gamma function which is defined as ( ) 1
0
x tt x dx ∞ − −Γ = ∫ e
If n is a positive integer then, ( )1 !n nΓ + =
The Gamma function is an extension of the normal factorial function. Here are a couple of quick facts for the Gamma function
( ) ( )
( ) ( ) ( ) ( ) ( )
1
1 2 1
1 2
p p p
p n p p p p n
p
π
Γ + = Γ
Γ + + + + − =
Γ
Γ =
L
Laplace_workshop_Week6(1).pdf
1
Name__________________________________________________Section________________________
Part 1: Given the following expressions for Y(s) find y(t)
1.1 𝑌(𝑠) = 𝑠−18
(𝑠+2)(𝑠−3)
1.2 𝑌(𝑠) = −3𝑠2−14𝑠+32
(𝑠+4)(𝑠2+4) =
𝐴
𝑠+4 +
𝐵𝑠+𝐶
𝑠2+4
1.3 𝑌(𝑠) = 2𝑠−3
𝑠2+2𝑠+10 hint complete square
2
1.4 𝑌(𝑠) = 90
(𝑠+5)(𝑠+2)2 repeated roots
Part 2: For the following problems solve the IVP - be careful of initial conditions and coefficients which
change in each problem
1.5 𝑦′′ + 6𝑦′ + 8𝑦 = 0 y’(0) = -4, y(0) = 1
1.6 𝑦′′ + 6𝑦′ + 8𝑦 = 0 y’(0) = 1, y(0) = 1
1.7 𝑦′′ + 6𝑦′ + 8𝑦 = 5 y’(0) = 1, y(0) = 1
3
1.8 𝑦′′ + 5𝑦′ + 6𝑦 = 5𝑒−5𝑡 y’(0) = 0, y(0) = 0
1.9 𝑦′ + 6𝑦 = t y(0) = 1