Answer
$3, -3, -3i, 3i$
Work Step by Step
This question asks for ALL zeros of the function
Given $P(x) = x^4 - 81$
Factor and set $P(x) = 0$
$(x^2 - 9) (x^2 + 9)$
$(x-3)(x+3)(x^2 + 9)$
$x^2 + 9 = 0$
$x = +/- 3i$
$x = 3, -3, -3i, 3i$
Thus the solutions are $3, -3, -3i, 3i$
