The number 16 has four fourth roots. Find them. I know they are \(2, -2, 2i, -2i\), but I can't explain. Please explain.
try multiplying them out.
eg
(-2i)^4 = -2i*-2i*-2i*-2i = 16*i^2*i^2 = 16*-1*-1 = +16
