Laplace Transform: Difference between revisions

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Standard Form:
:<math>F(s) = \mathcal{L} \left\{f(t)\right\}=\int_0^{\infty} e^{-st} f(t) \,dt </math>
Sample Functions:
:<math>F(s) = \mathcal{L} \left\{1\right\}=\int_0^{\infty} e^{-st} \,dt = </math> <math> \frac {1}{s}</math>
:<math>F(s) = \mathcal{L} \left\{1\right\}=\int_0^{\infty} e^{-st} \,dt = </math> <math> \frac {1}{s}</math>


:<math>F(s) = \mathcal{L} \left\{t^2\right\}=\int_0^{\infty} e^{-st} t^2 \,dt = </math> <math> \frac {n!}{s^{n+1}}</math>
:<math>F(s) = \mathcal{L} \left\{t^n\right\}=\int_0^{\infty} e^{-st} t^n \,dt = </math> <math> \frac {n!}{s^{n+1}}</math>
 
:<math>F(s) = \mathcal{L} \left\{e^{at}\right\}=\int_0^{\infty} e^{-st} e^{at} \,dt = </math> <math> \frac {1}{s-a}</math>
 
:<math>F(s) = \mathcal{L} \left\{sin(\omega t)\right\}=\int_0^{\infty} e^{-st} sin(\omega t) \,dt = </math> <math> \frac {\omega}{s^2+\omega^2}</math>
 
:<math>F(s) = \mathcal{L} \left\{cos(\omega t)\right\}=\int_0^{\infty} e^{-st} cos(\omega t) \,dt = </math> <math> \frac {s}{s^2+\omega^2}</math>
 
:<math>F(s) = \mathcal{L} \left\{t^n g(t)\right\}=\int_0^{\infty} e^{-st} t^n g(t) \,dt = </math> <math> \frac {(-1)^n d^n G(s)} {ds^n} </math> for n=1,2,...
 
:<math>F(s) = \mathcal{L} \left\{t sin(\omega t)\right\}=\int_0^{\infty} e^{-st} t sin(\omega t) \,dt = </math> <math> \frac {2 \omega s} {(s^2+\omega^2)^2} </math>
 
:<math>F(s) = \mathcal{L} \left\{t cos(\omega t)\right\}=\int_0^{\infty} e^{-st} t cos(\omega t) \,dt = </math> <math> \frac {s^2-\omega^2} {(s^2+\omega^2)^2} </math>
 
:<math>F(s) = \mathcal{L} \left\{g(t)\right\}=\int_0^{\infty} e^{-st} g(t) \,dt = </math> <math> \frac {1} {a} G \left(\frac {s} {a}\right)</math>
 
:<math>F(s) = \mathcal{L} \left\{e^{at} g(t)\right\}=\int_0^{\infty} e^{-st} e^{at} g(t) \,dt = </math> <math> G(s-a) </math>
 
:<math>F(s) = \mathcal{L} \left\{e^{at} t^n\right\}=\int_0^{\infty} e^{-st} e^{at} t^n \,dt = </math> <math> \frac {n!} {(s-a)^{n+1}} </math> for n=1,2,...

Revision as of 19:03, 11 January 2010

Standard Form:

F(s)={f(t)}=0estf(t)dt

Sample Functions:

F(s)={1}=0estdt= 1s
F(s)={tn}=0esttndt= n!sn+1
F(s)={eat}=0esteatdt= 1sa
F(s)={sin(ωt)}=0estsin(ωt)dt= ωs2+ω2
F(s)={cos(ωt)}=0estcos(ωt)dt= ss2+ω2
F(s)={tng(t)}=0esttng(t)dt= (1)ndnG(s)dsn for n=1,2,...
F(s)={tsin(ωt)}=0esttsin(ωt)dt= 2ωs(s2+ω2)2
F(s)={tcos(ωt)}=0esttcos(ωt)dt= s2ω2(s2+ω2)2
F(s)={g(t)}=0estg(t)dt= 1aG(sa)
F(s)={eatg(t)}=0esteatg(t)dt= G(sa)
F(s)={eattn}=0esteattndt= n!(sa)n+1 for n=1,2,...