Question

For what interval is the function f(x) = (20 + \sqrt{x}) / (\sqrt{20 + x}) continuous?

Answer 1

Try this solution:
1. according to the condition
$\left \{ {{x \geq 0} \atop {20+x\ \textgreater \ 0}} \right. \ =\ \textgreater \ \ x \geq 0.$
2. for more details see the attached graph.

Answer: [0;+oo)