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Groups > comp.soft-sys.math.maple > #271

Re: Annihilator Method answer not the same as in Maple 15

From Axel Vogt <&noreply@axelvogt.de>
Newsgroups comp.soft-sys.math.maple
Subject Re: Annihilator Method answer not the same as in Maple 15
Date 2011-12-26 08:49 +0100
Message-ID <9lqn97FbogU1@mid.individual.net> (permalink)
References <DLPJq.1901$ae4.1295@newsfe01.iad>

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On 26.12.2011 02:05, anon wrote:
> I plugged in:
>
> ode:=diff(y(t),t,t)+y(t)=cos(t);
> dsolve(ode);
>
> and the answer Maple 15 displayed was:
>
> y(t)=sin(t)_C2+cos(t)_C1+(1/2)*cos(t)+(1/2)*t*sin(t)
>
> I know this is the solution but when I use the Annihilator Method on
> paper, I get the same answer but without the (1/2)*cos(t)
>
> y(t) = c1*sin(t) + c2*cos(t) + (1/2)*t*sin(t)
>
> This answer also checks out but my question is:  What method does
> Maple 15 use to get the (1/2)*cos(t) term?
>
> Thank you.

After simplification it is just a different naming for the constants:

   sin(t)*_C2+cos(t)*_C1+(1/2)*cos(t)+(1/2)*t*sin(t);
   simplify(%, size);

     1/2*(2*_C1+1)*cos(t)+1/2*sin(t)*(2*_C2+t)


   c1*sin(t) + c2*cos(t) + (1/2)*t*sin(t);
   simplify(%, size);

     1/2*(2*c1+t)*sin(t)+c2*cos(t)

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Thread

Annihilator Method answer not the same as in Maple 15 anon <anon@anon.com> - 2011-12-26 01:05 +0000
  Re: Annihilator Method answer not the same as in Maple 15 Axel Vogt <&noreply@axelvogt.de> - 2011-12-26 08:49 +0100
    Re: Annihilator Method answer not the same as in Maple 15 anon <anon@anon.com> - 2011-12-26 15:39 +0000
  Re: Annihilator Method answer not the same as in Maple 15 "G. A. Edgar" <edgar@math.ohio-state.edu.invalid> - 2011-12-26 07:41 -0700
    Re: Annihilator Method answer not the same as in Maple 15 anon <anon@anon.com> - 2011-12-26 15:37 +0000

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