What is the Square root of negative 400?

Answer 1

- (400^.5) = -(20) = -20

you just do the square root of the number, and attach the negative in front.

and if you ever include the negative inside the square root, you'd have to deal with i, which is an imaginary number that signifies the square root of negative 1.

Answer 2

+/- 20i where i is the imaginary square root of -1.

Answer 3

324