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Rayne
02/22/07 11:45pm

Hi,
I'm trying to implement the Laplace transform using rule-based Mathematica programming with properties of the Laplace transform.

I have the folloing code:
l[c_, t_, s_] := c/s /;FreeQ[c,t];
l[a_+b_, t_, s_] := l[a,t,s] + l[b,t,s];
l[c_ a_, t_, s_] := c l[a,t,s] /; FreeQ[c,t];
l[t_^n_Integer, t_, s_] := n!/s^(n+1) /; n>0;
l[a_ t_^n_Integer, t_, s_] := (-1)^n D[l[a,t,s],{s,n}] /; n>0;

but for some reason, the line
l[t_^n_Integer, t_, s_] := n!/s^(n+1) /; n>0;
does not seem to work when n = 1, i.e. l[t,t,s].

It works for other positive n values, such as
l[t^2,t,s] Output: 2/s^3
l[t^3,t,s] Output: 6/s^4
l[2t^2,t,s] Output: 4/s^3

but for l[t,t,s], it gives me l[t,t,s] again. Or l[2t,t,s] gives 2 l[t,t,s].

I simply cannot see what is wrong with that line of code.

Please advise.

Thank you,

Regards,
Rayne

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Subject (listing for 'Laplace transform')
Author Date Posted
Laplace transform Rayne 02/22/07 11:45pm
Re: Laplace transform yehuda ben-s... 02/25/07 07:06am
Re: Re: Laplace transform Rayne 02/26/07 10:37am
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