i dont understand this

Answer:
[tex]x\geq 2[/tex]
Step-by-step explanation:
we have
[tex]y=\sqrt{2x-4}[/tex]
we know that
The radicand must be greater than or equal to zero
so
[tex]2x-4\geq 0[/tex]
Solve for x
Adds 4 both sides
[tex]2x-4+4\geq 0+4[/tex]
[tex]2x\geq 4[/tex]
Divide by 2 both sides
[tex]x\geq 2[/tex]
so
The domain is the interval for x ----> [2,∞)
All real numbers greater than or equal to 2