CAN SOMEONE PLS HELP ME I WILL MARK U BRAINLIEST

Answer:
[tex]x \geqslant 1[/tex]
Step-by-step explanation:
The expression in the square root should be greater than or equal to zero, because square root of a negative number does not give a real number.
[tex]x - 1 \geqslant 0 \\ x \geqslant 1[/tex]