Laplace Transform (inttrans Package)
restart
withinttrans:
assume⁡0<a
Introduction
The laplace transform has a number of uses. One of the main uses is the solving of differential equations. Let us first define the laplace transform:
convert⁡laplace⁡f⁡t,t,s,int
∫0∞f⁡t⁢ⅇ−t⁢sⅆt
The invlaplace is a transform such that invlaplace⁡laplace⁡f⁡t,t,s,s,w=f⁡w.
Algebraic, Exponential, Logarithmic, Trigonometric, Inverse Trigonometric, Hyperbolic, and Inverse Hyperbolic Functions
f:=randpoly⁡t+a,t,terms=3
f:=87⁢t2−56⁢t+a~2⁢t2
laplace⁡f,t,p
174p3−1344p5−672⁢a~p4−112⁢a~2p3
invlaplace⁡f,t,p
−112⁢a~⁢Dirac⁡3,p−56⁢Dirac⁡4,p−Dirac⁡2,p⁢−87+56⁢a~2
laplace⁡ⅇt,t,p
1p−1
invlaplace⁡ⅇ−a⁢t,t,p
Dirac⁡p−a~
laplace⁡ln⁡t,t,p
−γ+ln⁡pp
invlaplace⁡ln⁡t+1−ln⁡t,t,p
−ⅇ−p+1p
laplace⁡1⁢sin⁡3⁢tt14,t,p
38⁢π⁢3⁢2⁢ⅇ−98⁢p⁢−BesselI⁡34,98⁢p+BesselI⁡−14,98⁢pp3/2
invlaplace⁡1⁢sin⁡αtt,t,p
KelvinBei⁡0,2⁢α⁢p
laplace⁡arctan⁡t,t,p
Ci⁡p⁢sin⁡p−Ssi⁡p⁢cos⁡pp
invlaplace⁡arctan⁡1t,t,p
sin⁡pp
laplace⁡tanh⁡t,t,p
12⁢Ψ⁡12+p4−12⁢Ψ⁡p4−1p
invlaplace⁡1⁢sinh⁡αtt,t,p
12⁢cosh⁡2⁢α⁢p−cos⁡2⁢α⁢pπ⁢p
laplace⁡arcsinh⁡t,t,p
12⁢π⁢StruveH⁡0,p−BesselY⁡0,pp
invlaplace⁡1⁢arcsinh⁡tt,t,p
−∫p∞BesselJ⁡0,_U_Uⅆ_U
Fresnel's C & S Integral
laplace⁡FresnelC⁡t,t,p
14⁢AngerJ⁡12,p22⁢π−14⁢WeberE⁡12,p22⁢π+12⁢−sin⁡p22⁢π+cos⁡p22⁢πp
invlaplace⁡1⁢12−FresnelC⁡t22+12−FresnelS⁡t22t,t,p
Si⁡p24π
laplace⁡FresnelS⁡t,t,p
−1+LommelS2⁡1,12,p22⁢ππ
Exponential, Sine, and Cosine Integral
laplace⁡Ei⁡t,t,p
−ln⁡−p+1+ln⁡−p−ln⁡pp
invlaplace⁡Ei⁡t,t,p
−1p
laplace⁡Si⁡t,t,p
arccot⁡pp
laplace⁡Ci⁡t,t,p
−12⁢ln⁡p2+1p
Error Integral
laplace⁡erf⁡t,t,p
ⅇp24⁢erfc⁡p2p
invlaplace⁡1⁢erf⁡a⁢tt,t,p
Heaviside⁡−p+a~π⁢p
laplace⁡erfc⁡t,t,p
1−ⅇp24⁢erfc⁡p2p
invlaplace⁡1⁢ⅇt2⁢erfc⁡t+at,t,p
Heaviside⁡p−2⁢a~⁢erf⁡p2−erf⁡a~
Hankel's Functions 1 and 2
laplace⁡HankelH1⁡12,β⁢t,t,p
−I⁢2β⁢p−I⁢β
invlaplace⁡HankelH1⁡12,I⁢t,t,p
−1−I⁢Heaviside⁡p−1π⁢p−1
laplace⁡HankelH2⁡12,δ⁢t,t,p
2⁢Iδ⁢p+δ⁢I
invlaplace⁡HankelH2⁡12,−I⁢t,t,p
−1+I⁢Heaviside⁡p−1π⁢p−1
Bessel and Modified Bessel Functions
laplace⁡BesselJ⁡0,t⁢BesselJ⁡1,t,t,p
12−p⁢EllipticK⁡2p2+4π⁢p2+4
invlaplace⁡1⁢ⅇ−αt⁢BesselJ⁡0,βtt,t,p
BesselI⁡0,2⁢α2+β2−α⁢p⁢BesselJ⁡0,2⁢α2+β2+α⁢p
laplace⁡BesselK⁡0,t,t,p
arccos⁡p1−p2
invlaplace⁡BesselK⁡0,β⁢t,t,p
Heaviside⁡p−βp2−β2
laplace⁡BesselY⁡0,t,t,p
−2⁢ln⁡p2+1+pπ⁢p2+1
invlaplace⁡1⁢ⅇ−μt⁢BesselY⁡0,νtt,t,p
BesselI⁡0,2⁢μ2+ν2−μ⁢p⁢BesselY⁡0,2⁢μ2+ν2+μ⁢p−2⁢BesselJ⁡0,2⁢μ2+ν2+μ⁢p⁢BesselK⁡0,2⁢μ2+ν2−μ⁢pπ
laplace⁡BesselI⁡0,t,t,p
1−1+p2
invlaplace⁡ⅇ−a⁢t⁢BesselI⁡0,a⁢t,t,p
Heaviside⁡−p+2⁢a~−p⁢p−2⁢a~⁢π
Anger-Weber Functions
laplace⁡AngerJ⁡0,t,t,p
1p2+1
invlaplace⁡AngerJ⁡ν,t−BesselJ⁡ν,t,t,p
sin⁡ν⁢π⁢p2+1−pνπ⁢p2+1
Incomplete Gamma Function
invlaplace⁡1⁢Γ⁡ν,α⁢ttν,t,p
Heaviside⁡p−α⁢pν−1
Psi Function
invlaplace⁡Ψ⁡t,t,p
−12⁢coth⁡p2−12
Ordinary Differential Equations Using Laplace Transform
Here are some other examples of differential equations that can be solved.
de1:=ⅆ2ⅆt2⁢y⁡t+5⁢ⅆⅆt⁢y⁡t+6⁢y⁡t=0
de2:=ⅆ2ⅆt2⁢y⁡t+5⁢ⅆⅆt⁢y⁡t+6⁢y⁡t=5
de3:=ⅆ2ⅆt2⁢y⁡t+5⁢ⅆⅆt⁢y⁡t+6⁢y⁡t+ⅇt=sin⁡t
de5:=ⅆ2ⅆx2⁢y⁡x−y⁡x=sin⁡x
de6:=ⅆⅆt⁢v⁡t+2⁢t=0
de7:=ⅆⅆx⁢y⁡x−α⁢y⁡x=0
de8:=ⅆⅆx⁢y⁡x=z⁡x−y⁡x−x,ⅆⅆx⁢z⁡x=y⁡x;fcns:=y⁡x,z⁡x
de8:=ⅆⅆx⁢y⁡x=z⁡x−y⁡x−x,ⅆⅆx⁢z⁡x=y⁡x
fcns:=y⁡x,z⁡x
The solutions to the differential equations:
dsolve⁡de1,y⁡0=0,D⁡y⁡0=1,y⁡t,method=laplace
y⁡t=ⅇ−2⁢t−ⅇ−3⁢t
dsolve⁡de2,y⁡0=0,D⁡y⁡0=1,y⁡t,method=laplace
y⁡t=−32⁢ⅇ−2⁢t+56+23⁢ⅇ−3⁢t
dsolve⁡de3,y⁡0=0,D⁡y⁡0=1,y⁡t,method=laplace
y⁡t=−110⁢cos⁡t+110⁢sin⁡t+2315⁢ⅇ−2⁢t−2720⁢ⅇ−3⁢t−112⁢ⅇt
dsolve⁡de5,y⁡0=0,D⁡y⁡0=0,y⁡x,method=laplace
y⁡x=−12⁢sin⁡x+12⁢sinh⁡x
dsolve⁡de6,v⁡1=α,v⁡t,method=laplace
v⁡t=α−t−12−2⁢t+2
dsolve⁡de7,y⁡0=β,y⁡x,method=laplace
y⁡x=β⁢ⅇα⁢x
dsolve⁡de8,y⁡0=0,z⁡0=1,fcns,method=laplace
z⁡x=1+x−25⁢ⅇ−x2⁢5⁢sinh⁡x⁢52,y⁡x=1+15⁢ⅇ−x2⁢−5⁢cosh⁡x⁢52+5⁢sinh⁡x⁢52
dsolve⁡de8,y⁡0=1,z⁡0=0,fcns,method=laplace
z⁡x=1+x−15⁢ⅇ−x2⁢5⁢cosh⁡x⁢52+5⁢sinh⁡x⁢52,y⁡x=1−25⁢ⅇ−x2⁢5⁢sinh⁡x⁢52
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