Why the command

does not return eps???

How can I simplify expressions like this?

is possible to continue a numerical integration from a know point and add the solution the the know one?
i.e.
if I have:
P=dsolve(... range=0..1)
and I want continue the integration until 3 (so without reintegrate the 0..1 interval) and add that solution tothe first one.

If i use dsolve for solve numerically a ODEs with classical methods, it seems that it isn't possible use the option range=a..b, so for every plot that i want graph using odeplot, i need to integrate the equation! Is there any way to store the results as dsolve do when is used the range option with rk45 method?

Hi
is possible to save the dsolve results for a numerical integration? so that i can reload them with out re-run the integrator.
 

does any one know if it is possible to solve numerically a ODE sys write in matrix form without first evaluate is as a set of equation?

for example my system is y'(x)=A(x,y).b(x,y)
where y'(x) and b(x,y) are Vectors and A(x,y) is a matrix

so i would solve it numerically without doing first the dotproduct symbolically. I woud do this because my system equation is constitudet not from a simple matrix.vector but by large matrix inversion so do it symbolically first take a lot of time and memory.