Use N[(25/10)^125,30] to get the high-precision answer.
The input has to be specified to at least the desired precision. Mathematica treats 2.5 as a machine-precision number.
Hope that helps, Tom
On Sun, 17 Feb 2013 09:08:38 +0000 (UTC), Blaise F Egan <firstname.lastname@example.org> wrote:
>I am trying to evaluate 2.5^125 to high precision. > >R gives 5.527147875260445183346e+49 as the answer but Mathematica with N[2.5^125,30] gives 5.52715*10^49 and says that is to machine precision. > >I am inexperienced at Mathematica. Am I doing something silly? > >Blaise