Answer :
I don't know if your saying y= √(x-10) or y= √(x) - 10. But I'll do both
Domain for √(x-10): [10, ∞)
Domain for √(x) - 10: [0, ∞)
Domain for √(x-10): [10, ∞)
Domain for √(x) - 10: [0, ∞)