3 years, 9 days

## That was not what I wanted. As I...

That was not what I wanted. As I said, coefficients are long and ugly expressions in their own right, and I do not want to have to retype them both in arguments and in assumptions. Below is one grossly simplified example of what I have to handle (don't know why mtaylor() does not work while mtaylor(series()) does, but anyways ...).

All that I want is to return that solution that has the form .

 (1)

 (2)

## But after a reboot?!?...

This is getting weird. Re-running (executing using !!!) did not change a thing. Editing, saving, !!!ing did not change the errors.

But last night I had to reboot the computer for an update of some other software, and then when I relaunched Maple this morning and opened the SystemGoesWrong.mw file - the errors were still there, but everything was updated using !!! and the errors disappeared.

What is going on? Is it so that "restart" does not really restart? Should I need to close Maple and reopen it?

## And is this behaviour as expected?...

As the integral is solvable, I fiddled around a bit with it. I tried the "implicit" option:

```restart; assume(nu > 2, beta > 0, lambda > 0, delta > 0, y >= 0);
ODEh := beta+y+(D(h))(y) = nu*((lambda+beta+y)^2-delta*h(y))^(1/2);
solimp := simplify(dsolve(ODEh, implicit));
```

Two puzzling elements in the output:

• ln(negative). Why? There was a reason for the "assume".
• The delta~+2 denominator. That does not look very simplified?

Afterwards, I played around with
simplify(value(solimp))
simplify(value([copy+pasted the output after having fixed the delta~+2))
They do of course yield ugly output (and quite different formulae), but I don't immediately spot any ln(negative).

## @_Maxim_ So in order to visually co...

@_Maxim_ So in order to visually compare output, I use "rhs" in the second line. New document, paste

```restart; assume(nu > 2, beta > 0, lambda > 0, delta > 0, y >= 0);
rhs(simplify(dsolve(beta+y+(D(h))(y) = nu*((lambda+beta+y)^2-delta*h(y))^(1/2))));
applyrule(e::RootOf = 'applyop(simplify, 1, e)', %)```

... but it makes no difference.

Then copy the RootOf parenthesis, paste it inside the parentheses of simplify() - and then I get a simplification. This one simplifies:

`simplify(Intat((2*(2*_a*`&delta;`^2+`&nu;`*sqrt(-_a*`&delta;`^3-4*_a*`&delta;`^2-4*_a*`&delta;`+1)+8*_a*`&delta;`+8*_a+1))*(`&delta;`+2)*`&lambda;`/(`&nu;`^2*_a*`&delta;`^3+4*_a^2*`&delta;`^4+4*`&nu;`^2*_a*`&delta;`^2+32*_a^2*`&delta;`^3+4*`&nu;`^2*_a*`&delta;`+96*_a^2*`&delta;`^2+128*_a^2*`&delta;`+4*_a*`&delta;`^2-`&nu;`^2+64*_a^2+16*_a*`&delta;`+16*_a+1), _a = _Z)*`&delta;`+2*`&lambda;`*ln(-`&beta;`*`&delta;`-y*`&delta;`-2*`&beta;`-2*y-2*`&lambda;`)+_C1*`&delta;`+2*Intat((2*(2*_a*`&delta;`^2+`&nu;`*sqrt(-_a*`&delta;`^3-4*_a*`&delta;`^2-4*_a*`&delta;`+1)+8*_a*`&delta;`+8*_a+1))*(`&delta;`+2)*`&lambda;`/(`&nu;`^2*_a*`&delta;`^3+4*_a^2*`&delta;`^4+4*`&nu;`^2*_a*`&delta;`^2+32*_a^2*`&delta;`^3+4*`&nu;`^2*_a*`&delta;`+96*_a^2*`&delta;`^2+128*_a^2*`&delta;`+4*_a*`&delta;`^2-`&nu;`^2+64*_a^2+16*_a*`&delta;`+16*_a+1), _a = _Z)+2*_C1)`

Maple 2016.2 (insert Friday 13th joke here) and ClumsyUser 2017.11 ...

## @Carl Love  Everything is symbolic...

Everything is symbolic. The only number is the "0" in the nonnegativity conditions. Oh, and indices.

(And the problems are the same ... I don't think I messed up signs/parentheses?)

 Page 1 of 1
﻿