Answer
$(-4, 1)$
Work Step by Step
$x^4 + 3x^3 - 3x^2 + 3x -4 <0$
Find the roots of the function (graph is attached below with zeros)
$x = -4, 1$
Thus the factoring is $(x+4)(x-1)(x^2 + 1)$
Test numbers in between those zero values to determine if the function is negative or positive
(-∞, -4) $(-)(-)(+) = (+)$
(-4, 1) $(+)(-)(+) = (-)$
(1, ∞) $(+)(+)(+) = (+)$
Thus the solution is $(-4, 1)$
