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Re: Using N function

• To: mathgroup at smc.vnet.net
• Subject: [mg76282] Re: [mg76270] Using N function
• From: Carl Woll <carlw at wolfram.com>
• Date: Sat, 19 May 2007 04:30:38 -0400 (EDT)
• References: <200705181031.GAA13821@smc.vnet.net>

kkwweett wrote:

>Good morning Mathematica users,
>
>
>Can anyone tell me, please, which of a),b) or c) is wrong :
>
>a)
><MathematicaHelp>
><quote>
>
>N[expr] is equivalent to N[expr, MachinePrecision].
>
></quote>
></MathematicaHelp>
>
>b)
>In[1]:=N[Exp[Sqrt[163 ]Pi] - 640320^3]
>Out[1]=256.
>
>
>c)
>In[2]:=N[Exp[Sqrt[163 ]Pi] - 640320^3,$MachinePrecision]
>Out[2]=743.9999999999993
>
>?
>
>Thank you
>  
>
None of them are wrong. Perhaps you meant to use the following in part c?

In[32]:= N[Exp[Sqrt[163] Pi] - 640320^3, MachinePrecision]
Out[32]= 256.

Note the use of MachinePrecision instead of $MachinePrecision.

Carl Woll
Wolfram Research

• References:
  • Using N function
    • From: kkwweett <kkwweett@hotmail.fr>