Fricas misses an opportunity for simplifying results using the Pythagorean trigonometric identity

[Neven Sajko]

This is basically a bug report or feature request, I am posting it
here since it seems non-developers are not welcome on the Fricas
Github??

Fricas 1.3.5 gives an overcomplicated particular solution for the
differential equation here: "solve(D(y(x), x, 3) - 6 * D(y(x), x, 2) +
D(y(x), x) - 6 * y(x) = -6 * x^2 + 2 * x, y, x)"

Fricas could factor out 36 * x^2 - 74 and then apply the Pythagorean
trigonometric identity (sin(x)^2 + cos(x)^2 = 1), giving the much
simpler expression x^2 - 2 as the particular solution to the ODE.

Regards,
Neven Sajko

[Ralf Hemmecke]

On 6/10/19 6:32 PM, Neven Sajko wrote:
> This is basically a bug report or feature request, I am posting it
> here since it seems non-developers are not welcome on the Fricas
> Github??

??? What does that mean?

FriCAS at Github is a MIRROR of the official sourceforge svn repository.
Development (unfortunately) still happens via SVN. So that only says
that not all developers get notified when someone posts at github. I
therefore must everyone point to the official mailing list (which you
are using now).

Ralf