Use "sqrt(expression)" when attempting to render in plain text. The way you did it, your function is ambiguous because it is not clear how much of the expression following the surd is actually part of the radicand.
I'm going to assume you meant:
This function is defined for all real numbers such that .
Just solve the inequality for and express the result in whatever way you need to.
John
My calculator said it, I believe it, that settles it
