Re: Question about precision.
- To: mathgroup at smc.vnet.net
- Subject: [mg38452] Re: Question about precision.
- From: Nigel King <king at dircon.co.uk>
- Date: Mon, 16 Dec 2002 02:20:43 -0500 (EST)
- References: <atcasb$3m0$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In <atcasb$3m0$1 at smc.vnet.net> Wen-Feng Hsiao wrote: > I try to find the square root of 1.3, but obtain an not so correct > answer. Could someone point me how to do? My trials are the > followings. In order to display a number to its full precision, it is often necessary to use NumberForm In[1]:= NumberForm[Sqrt[1.3], 50] Out[1]//NumberForm= "1. 140175425099138" An alternative is to specify the precision of 1.3 using 1.3`30 In[2]:= Sqrt[1.3`30] Out[2]= 1.140175425099137979136049025567 Note that the internally held answer for Sqrt[1.3] is much more accurate than the displayed number. In[3]:= x = Sqrt[1.3] Out[3]= 1.14018 In[4]:= NumberForm[x*x, 50] Out[4]//NumberForm= "1.3" I hope this helps --- Nigel