What is the square root of-256? And how did you get this answer

There is no square root with real number for a negative number, but you can use imaginary numbers such as i which means the square root of - 1

so you can factor the - 1 out and get 256

you factor 256 into 2*2*2*2*2*2*2*2 or 2^8

so if you group them into (2^2) (2^2) (2^2) (2^2) then square root all of them you get 2^4 or 16

but there is the immaginary part so the answer is 16i