Question

The value of √-9 is not -3 because_______.

A. 9^2 not congruent to -3
B. (-3)^2 not congruent to -9
C. 3^2 not congruent to -9
D. (-9)^2 not congruent to -3

Answer 1

The value of √-9 is not -3 because B. (-3)^2 not congruent to -9.

This is the answer because, (-3)^2 = 9 NOT -9. Any negative squared is equal to the positive squared. E.g. 2^2=4 & (-2)^2=4. Another tip is that in the number in the square root sign is negative the answer is no solution as it is impossible to square a number and get a negative answer.

Answer 2

B, because -3^2 is not -9. -3*-3 = 9, square roots of negative numbers aren't possible, because no number squared can be equal to them. Instead, they are expressed in terms of "i", which is defined as

i^2 = -1