Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!lll-lcc!mordor!styx!ames!oliveb!intelca!mipos3!pinkas From: pinkas@mipos3.UUCP (Israel Pinkas) Newsgroups: comp.lang.c Subject: Re: Is .2 irrational? Message-ID: <361@mipos3.UUCP> Date: Thu, 8-Jan-87 12:20:24 EST Article-I.D.: mipos3.361 Posted: Thu Jan 8 12:20:24 1987 Date-Received: Fri, 9-Jan-87 01:39:37 EST References: <442@catnip.UUCP> <7456@utzoo.UUCP> <153@piaget.UUCP> <1384@bunker.UUCP> <568@brl-sem.ARPA> Reply-To: pinkas@mipos3.UUCP (Israel Pinkas) Organization: Intel, Santa Clara, CA Lines: 23 In article <568@brl-sem.ARPA> ron@brl-sem.ARPA (Ron Natalie) writes: >Gee, how do you deal with 1/3? I'm not sure how I do that even on >a decimal computer. Perhaps you meant that can handle an exact represntation >of all fractions of the form INTEGER/(Power of 10) People, I think that you are forgetting the definition of the term rational. Rational numbers are defined to be numbers which can be represented as a fraction of two integers. Thus, 1/3, 22/7, and 42 are all rational numbers, whereas e, pi, and i, are not. What the original poster was asking, I think, is whether it is possible to represent the number 0.2 (decimal) in binary with a fixed (read limited) number of digits without losing accuracy. The answer is no. The reason is that 0.2 is really 1/5, and 5 is not a divisor of any power of two. (5 is a divisor of a power of 10, 10^1, thus 1/5 can be represented in decimal with only 1 decimal place.) -Israel -- ---------------------------------------------------------------------- UUCP: {amdcad,decwrl,hplabs,oliveb,pur-ee,qantel}!intelca!mipos3!pinkas ARPA: pinkas%mipos3.intel.com@relay.cs.net CSNET: pinkas%mipos3.intel.com