Re: [Boost-users] math tools roots

Subject: Re: [Boost-users] math tools roots
From: Matwey V. Kornilov (matwey.kornilov_at_[hidden])
Date: 2011-10-09 13:04:39

This routine checks that the interval is small enough. We check interval 
that bounds the root that we are looking for. Now, let me consider interval 
whose lower and upper bounds are equal. In such case we find our root 
exactly. There is no way to make it more precise.

and, actually let a=b=x, 

lim_{x->0} ((x-x)/min(|x|,|x|)) = lim_{x->0} (0/min(|x|,|x|)) = lim_{x->0}
(0) = 0 

Steven Watanabe wrote:
> 
> What exactly do you mean by "the relative length of
> the interval tends to zero?"
> 
> lim_{(a,b)->(0,0)} |a-b| / min(|a|, |b|)
> 
> doesn't exist.
> 
> In Christ,
> Steven Watanabe