When a system of symbolic equations of order five or greater is solved by Maple, the function RootOf compares in the solutions. In order to get an explicit form of all the possibles solutions I set the option of the solve command:

_EnvExplicit:=true;

The problem is that sometimes the solutions are very complex, involving atan with uge arguments.

My problem is to simplify these kind of solutions.

The only method that gave me some results was:

Expand->"one of the specific simplifying commands as 'factor' "->simplify.

What I have done wrong?

eq := [piecewise(p(t) < prec, p(t) = C1*exp(function), p(t) >= prec, p(t) = C1*exp(function))]

params := [C1 = .2, prec = 100]

sys := DynamicSystems[AlgEquation](eq, inputvariable = [function], outputvariable = [p(t)])

But I recieve the following error message:

Error, (in DynamicSystems:-AlgEquation) cannot match the arguments to an appropriate system

If I try to solve the following differential equation with simbolic parameters:

IC := p(0) = condizIni

ode := diff(p(t), t) = (QIn-QOut-derV)/((1/Boil+1/Bwall+percair/(m*p(t)))*V)

func := rhs(dsolve({IC, ode}))

the result I get from Maple12 have the following member inside it:

LambertW(_Z7, _Z)

but I do not know what are _Z7 and _Z.

Where I can find the expression of these parameters?

Why Maple added these parameters?