imposible

4i

happyfeet wrote: what is the answer to the square root of -16?

The square root of a negative number does not exist.
So square root of -16=undefined.

sqrt16 sqrt -1 = 4i

sqrt of -1 is imaginary number by definition

If one asks what is sqrt(-16) over the real numbers the correct answer is that it does not exist.

If one asks what is sqrt(-16) over the complex numbers the answer is 4i