## 75 Reputation

1 years, 310 days

## More complicated case...

It works for this case. But can you try this one? Solve each variables in terms of parameters "x"

## @dharr  Thank you so much! Really ...

Thank you so much! Really appreciate your code!!

## A further question...

But can I ask for a further question? How can I know which variables are to be chosen to be variables to solve for and which are free variables? For example in this case, if I choose b[0],b[1],b[2] to be variables to solve for, I would get an empty solution set.

## @Carl Love But I indeed look for a ...

@Carl Love But I indeed look for a six variables system. Three equations for six variables, t is treated as constant. It's an overdetermined system.

## Mistake in (71) tanh(arctanh(y)/2)...

Mistake in (71) tanh(arctanh(y)/2)

## A possible explanation...

If the ODE can be solved directly, the polysols first calculate the general solutions and find poly solutions in the general solutions so the singular solution is ignored. If the ODE cannot be solved directly, the polysols use some algorithm to find some particular singular solutions.

## Some assumptions should be added...

the parameters a=c,b=d

## @Carl Love Thank you!...

@Carl Love Thank you!