Laplace Transform (inttrans Package)
restart
withinttrans:
assume0<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:
convertlaplaceft,t,s,int
∫0∞ftⅇ−tsⅆt
The invlaplace is a transform such that invlaplacelaplaceft,t,s,s,w=fw.
Algebraic, Exponential, Logarithmic, Trigonometric, Inverse Trigonometric, Hyperbolic, and Inverse Hyperbolic Functions
f:=randpolyt+a,t,terms=3
f:=87t2−56t+a~2t2
laplacef,t,p
174p3−1344p5−672a~p4−112a~2p3
invlaplacef,t,p
−112a~Dirac3,p−56Dirac4,p−Dirac2,p−87+56a~2
laplaceⅇt,t,p
1p−1
invlaplaceⅇ−at,t,p
Diracp−a~
laplacelnt,t,p
−γ+lnpp
invlaplacelnt+1−lnt,t,p
−ⅇ−p+1p
laplace1sin3tt14,t,p
38π32ⅇ−98p−BesselI34,98p+BesselI−14,98pp3/2
invlaplace1sinαtt,t,p
KelvinBei0,2αp
laplacearctant,t,p
Cipsinp−Ssipcospp
invlaplacearctan1t,t,p
sinpp
laplacetanht,t,p
12Ψ12+p4−12Ψp4−1p
invlaplace1sinhαtt,t,p
12cosh2αp−cos2αpπp
laplacearcsinht,t,p
12πStruveH0,p−BesselY0,pp
invlaplace1arcsinhtt,t,p
−∫p∞BesselJ0,_U_Uⅆ_U
Fresnel's C & S Integral
laplaceFresnelCt,t,p
14AngerJ12,p22π−14WeberE12,p22π+12−sinp22π+cosp22πp
invlaplace112−FresnelCt22+12−FresnelSt22t,t,p
Sip24π
laplaceFresnelSt,t,p
−1+LommelS21,12,p22ππ
Exponential, Sine, and Cosine Integral
laplaceEit,t,p
−ln−p+1+ln−p−lnpp
invlaplaceEit,t,p
−1p
laplaceSit,t,p
arccotpp
laplaceCit,t,p
−12lnp2+1p
Error Integral
laplaceerft,t,p
ⅇp24erfcp2p
invlaplace1erfatt,t,p
Heaviside−p+a~πp
laplaceerfct,t,p
1−ⅇp24erfcp2p
invlaplace1ⅇt2erfct+at,t,p
Heavisidep−2a~erfp2−erfa~
Hankel's Functions 1 and 2
laplaceHankelH112,βt,t,p
−I2βp−Iβ
invlaplaceHankelH112,It,t,p
−1−IHeavisidep−1πp−1
laplaceHankelH212,δt,t,p
2Iδp+δI
invlaplaceHankelH212,−It,t,p
−1+IHeavisidep−1πp−1
Bessel and Modified Bessel Functions
laplaceBesselJ0,tBesselJ1,t,t,p
12−pEllipticK2p2+4πp2+4
invlaplace1ⅇ−αtBesselJ0,βtt,t,p
BesselI0,2α2+β2−αpBesselJ0,2α2+β2+αp
laplaceBesselK0,t,t,p
arccosp1−p2
invlaplaceBesselK0,βt,t,p
Heavisidep−βp2−β2
laplaceBesselY0,t,t,p
−2lnp2+1+pπp2+1
invlaplace1ⅇ−μtBesselY0,νtt,t,p
BesselI0,2μ2+ν2−μpBesselY0,2μ2+ν2+μp−2BesselJ0,2μ2+ν2+μpBesselK0,2μ2+ν2−μpπ
laplaceBesselI0,t,t,p
1−1+p2
invlaplaceⅇ−atBesselI0,at,t,p
Heaviside−p+2a~−pp−2a~π
Anger-Weber Functions
laplaceAngerJ0,t,t,p
1p2+1
invlaplaceAngerJν,t−BesselJν,t,t,p
sinνπp2+1−pνπp2+1
Incomplete Gamma Function
invlaplace1Γν,αttν,t,p
Heavisidep−αpν−1
Psi Function
invlaplaceΨt,t,p
−12cothp2−12
Ordinary Differential Equations Using Laplace Transform
Here are some other examples of differential equations that can be solved.
de1:=ⅆ2ⅆt2yt+5ⅆⅆtyt+6yt=0
de2:=ⅆ2ⅆt2yt+5ⅆⅆtyt+6yt=5
de3:=ⅆ2ⅆt2yt+5ⅆⅆtyt+6yt+ⅇt=sint
de5:=ⅆ2ⅆx2yx−yx=sinx
de6:=ⅆⅆtvt+2t=0
de7:=ⅆⅆxyx−αyx=0
de8:=ⅆⅆxyx=zx−yx−x,ⅆⅆxzx=yx;fcns:=yx,zx
de8:=ⅆⅆxyx=zx−yx−x,ⅆⅆxzx=yx
fcns:=yx,zx
The solutions to the differential equations:
dsolvede1,y0=0,Dy0=1,yt,method=laplace
yt=ⅇ−2t−ⅇ−3t
dsolvede2,y0=0,Dy0=1,yt,method=laplace
yt=−32ⅇ−2t+56+23ⅇ−3t
dsolvede3,y0=0,Dy0=1,yt,method=laplace
yt=−110cost+110sint+2315ⅇ−2t−2720ⅇ−3t−112ⅇt
dsolvede5,y0=0,Dy0=0,yx,method=laplace
yx=−12sinx+12sinhx
dsolvede6,v1=α,vt,method=laplace
vt=α−t−12−2t+2
dsolvede7,y0=β,yx,method=laplace
yx=βⅇαx
dsolvede8,y0=0,z0=1,fcns,method=laplace
zx=1+x−25ⅇ−x25sinhx52,yx=1+15ⅇ−x2−5coshx52+5sinhx52
dsolvede8,y0=1,z0=0,fcns,method=laplace
zx=1+x−15ⅇ−x25coshx52+5sinhx52,yx=1−25ⅇ−x25sinhx52
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