What is the domain and range for y = sqrt(x-3)?

1 Answer
May 18, 2015

You know $\sqrt{a}$ is well defined iff $a \ge 0$ (otherwise its image is not in $\mathbb{R}$), so $y$ is well defined iff

$x - 3 \ge 0 \implies x \ge 3$

Its range is the range of the square root, so $y \ge 0$