Question

Evaluate the following.
let me know if its "Not a real number"
-√81
√-16

Answer 1

Explanation:

(1)

-√81 = -9 (although you could argue that it's ± 9, since 81 has two square roots: 9 and -9). Real number.

(2) √(-16) is imaginary, and the value is i·4 (or -i·4). Not a real number.

Answer 2

-9, Undefined

Explanation:

-√81

-√9^2

-9