@Ioan: F2 seems to be an unknown, so it is ok to be undefined.
The problem is that you use a symbolic solver and feed it with floating point equations. What do you expect? The solver is forced to resort to extremely long rational numbers in order to avoid cancellation of significant digits,
Use a numerical solver instead or set everything up to the solver command to symbolic optimization.
Then you get an exact solution, which is reasonably compact.

Here is an old SMath sheet of mine for planar truss structures.
Fachwerk Kran.sm (78.17 KiB) downloaded 10 time(s).
Edited 3/30/2026 9:03:12 PM
Technische Mechanik mit SMath Studio: https://link.springer.com/book/10.1007/978-3-658-50592-9