What three numbers, other than the number one, when raised to the fourth power, equal one?

Question

What three numbers, other than the number one, when raised to the fourth power, equal one?

Answer 1

Are imaginary numbers allowed?

If so, then the three numbers are :

-1 because (-1)(-1)(-1)(-1) = +1

i because (i)(i)(i)(i) = i² i² = (-1)(-1) = +1

-i because (-i)(-i)(-i)(-i) =( +i² )(+i²) = (-1)(-1) = +1