# Domain and Range

• September 8th 2009, 03:40 PM
Morgan82
Domain and Range
Had my first calc test today!
I feel pretty good about it.
One question...

y = 2/ sqrt(x-3)

find domain and range...

Can someone tell me what it is... I hope I did it right.
• September 8th 2009, 04:02 PM
pickslides
$x \in (3,\infty)$

$y \in \mathbb{R} /{0}$
• September 8th 2009, 04:09 PM
luobo
Quote:

Originally Posted by pickslides
$x \in (3,\infty)$

$y \in \mathbb{R} /{0}$

Shouldn't $y$ be greater than zero?
• September 8th 2009, 05:57 PM
pickslides
Given the range of the function is the domain of the inverse then y can be negative

$f(x)= \frac{2}{\sqrt{x-3}}$

$f^{-1}(x) = \frac{4}{x^2}+3$