<![CDATA[Feature request: Solving linear systems of first order DE's]]>
https://help.geogebra.org/topic/feature-request-solving-linear-systems-of-first-order-de-s
Sun, 04 Dec 2016 17:44:31 +0000Mon, 05 Aug 2013 19:51:42 +0000Zend_Feed<![CDATA[There is no command in giac/xcas for that but you can do it via Laplace transform. Let M be the matrix of the system M:=[[-1,1],[2,4]; [U,V]:=(p-M)^(-1)*[u,v]; A:=invlaplace(U,p,x); B:=invlaplace(V,p,x); Check: simplify([diff(A,x),diff(B,x)]-M*[A,B]); subst(A,x,0); subst(B,x,0) If you have a second member, add the Laplace transform to [u.v]]]>
https://help.geogebra.org/topic/feature-request-solving-linear-systems-of-first-order-de-s#comment-137459
Mon, 19 Aug 2013 21:35:57 +0000<![CDATA[Your example is slightly over my head, furthermore I suspect there are errors in it. Matrices are handled in the following way in GeoGebra, using curly braces rather than square brackets. However there seems to be no such command as InvLaplace in GeoGebra. If there is one in Giac then it perhaps it is not implemented yet? I was hoping to find solutions to the Lotka-Volterra equations without doing a numerical solution using the spreadsheet which is rather tehnical for the students. Involving inverse laplace transforms will be even more technical I'm afraid.]]>
https://help.geogebra.org/topic/feature-request-solving-linear-systems-of-first-order-de-s#comment-137461
Tue, 20 Aug 2013 20:28:21 +0000<![CDATA[Sorry, I should have precised that the commands were giac commands, not geogebra ones. Might be useful for a future geogebra interface to solve linear differential systems with constant coefficients, like the linearization of a Volterra system near an equilibrum (for non linear or non constant coefficients, there are in general no symbolic solution, but numerical approximations are also available in giac for non-stiff problems).]]>
https://help.geogebra.org/topic/feature-request-solving-linear-systems-of-first-order-de-s#comment-137463
Wed, 21 Aug 2013 21:30:44 +0000<![CDATA[Update: GeoGebra now supports inverse Laplace transform https://www.geogebra.org/ma... https://www.geogebra.org/ma...]]>
https://help.geogebra.org/topic/feature-request-solving-linear-systems-of-first-order-de-s#comment-208614
Sun, 04 Dec 2016 17:44:32 +0000