Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!caip!brl-adm!brl-smoke!smoke!rbj@icst-cmr From: rbj@icst-cmr (Root Boy Jim) Newsgroups: net.lang.c Subject: Re: LPow correction Message-ID: <1843@brl-smoke.ARPA> Date: Mon, 30-Jun-86 17:42:16 EDT Article-I.D.: brl-smok.1843 Posted: Mon Jun 30 17:42:16 1986 Date-Received: Tue, 1-Jul-86 03:56:58 EDT Sender: news@brl-smoke.ARPA Lines: 30 In article <1604@brl-smoke.ARPA> gwyn@BRL.ARPA (VLD/VMB) writes: >Jim Cottrell pointed out to me that 0^0 should be 1, not 0 >as I had it in my posted LPow() function. Sorry to bring it up, but Jim Cottrell is wrong, 0^0 is an indeterminate form, as you will find by looking in any elementary calculus book (eg. Anton). This form should be treated just as 0/0. Sorry to disappoint you, but old Root Boy is correct. It depends on the context. If we are asking for the value of a function at a given point and it is an indeterminate form, it may be found to have a value by using L'Hopital's rule. On the other hand, if we ask for the value of the constant expression 0^0 we must figure out what that `really' means. As I mentioned, defining this expression to be unity is useful for infinite series expansions. Since Doug Gwyn was writing an integer power function he chose the expression lim x->0 x^x to evaluate 0^0 because that was what he was interested in. He could have chosen x^(sin x) as well, but why should he? Tim Graham Jet Propulsion Laboratory (818) 577-6689 Go ask a mathemetician, and if you don't believe him, try Carl Sagan. (Root Boy) Jim Cottrell LBJ, LBJ, how many JOKES did you tell today??! Looks like Zippy misspelled my name :-)