On 6/21/2011 8:43 AM, Richard Fateman wrote:
> The issue here is, to some extent, not solve but how much
> simplification should be used automatically by any command (including
> solve) in processing. One can try any or all of a substantial number
> of simplification programs, including ratsimp, fullratsimp, trigsimp,
> exponentialize, factor .... at every juncture, including "is", "if",
> "solve" ...
>
> or
>
> expect that the user will occasionally make a choice of some
> transformation before calling the command.
>
>
> Solve is perhaps unusual in that it may eventually conclude something
> like "nope, I couldn't do that" and could then try some extra tools.
>
> But just factoring the input to solve is probably NOT a good idea,
> given the potential expense of factoring when it is pointless.
>
> RJF
>
>
Agree completely. For example, normally we work with the log of the
binomial (maximizing likelihood of p):
lf : y*log(p)+(N-y)*log(1-p);
dlf : diff(lf,p);
solve(dlf,p);
In this case, solve yields the 'right answer' (p=y/N).