LPow correction

Root Boy Jim rbj at icst-cmr
Tue Jul 1 07:42:16 AEST 1986


	In article <1604 at brl-smoke.ARPA> gwyn at 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		<rbj at icst-cmr.arpa>
	LBJ, LBJ, how many JOKES did you tell today??!

Looks like Zippy misspelled my name :-)



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