Question

find the domain of g(y)= squareroot y-10

Answer 1

since g(y) is not real when y < 0, then domain is all real numbers >= 0

Answer 2

if this is
\[g(y)=\sqrt{y-10}\] so solve by setting
\[y-10\geq0\] making
\[y\geq 10\] as the domain