Find the domain of $LaTeX: \displaystyle f(x) = \sqrt{9 x - 9} - 12$ . Write the solution in interval notation.

The domain of a radical function is the solution to the inequality radicand $LaTeX: \displaystyle \geq 0$ . The inequality is $LaTeX: \displaystyle 9 x - 9 \geq 0$ . Isolating $LaTeX: \displaystyle x$ gives $LaTeX: \displaystyle 9 x \geq 9$ Dividing to finish isolating $LaTeX: \displaystyle x$ gives $LaTeX: \displaystyle x \geq 1$ . The domain is $LaTeX: \displaystyle \left[1, \infty\right)$