Re: domain notation for a function

[William Elliot]

On Sat, 30 Dec 2006 sean_in_cali@xxxxxxxxx wrote:

> Define the domain for a composite function  f ( f (x) )
>
> if f (x) =  sqrt ( x^2 -1 )
>
All complex numbers.  If you want real numbers, then
        1 <= x^2
to make f(x) real and
        1 <= x^2 - 1
to make f(f(x)) real since
        f(x)^2 = x^2 - 1.