Найдите область определения функции y=sqrt(x^2-9)-sqrt(x-3)

[latex]y=\sqrt{x^2-9}-\sqrt{x-3}\\\\OOF:\; \; \left \{ {{x^2-9 \geq 0} \atop {x-3 \geq 0}} \right. \; \left \{ {{(x-3)(x+3) \geq 0} \atop {x \geq 3}} \right. \; \left \{ {{x\in (-\infty ,-3\, ]\cup [\, 3,+\infty )} \atop {x\in [\, 3,+\infty )}} \right. \\\\x\in [3,+\infty )[/latex]