Answer :

Let's evaluate each expression step by step.

1. Evaluate [tex]\(-\sqrt{9}\)[/tex]:
- Start by finding the square root of 9. The square root of 9 is 3 because [tex]\(3 \times 3 = 9\)[/tex].
- Then, apply the negative sign:
[tex]\[ -\sqrt{9} = -3 \][/tex]
- So, [tex]\(-\sqrt{9} = -3\)[/tex].

2. Evaluate [tex]\(\sqrt{-1}\)[/tex]:
- The square root of a negative number is not a real number.
- Specifically, the square root of -1 is defined as the imaginary unit, denoted by [tex]\(i\)[/tex], in complex number theory. However, in the context of real numbers, it is not a real number.
[tex]\[ \sqrt{-1} = \text{Not a real number} \][/tex]

Putting it all together, we have:
- [tex]\(-\sqrt{9} = -3\)[/tex]
- [tex]\(\sqrt{-1} = \text{Not a real number}\)[/tex]

Thus, the evaluated expressions are:
[tex]\[ \begin{array}{l} -\sqrt{9} = -3 \\ \sqrt{-1} = \text{Not a real number} \end{array} \][/tex]