## Algebra and Trigonometry 10th Edition

$+\sqrt 2, -\sqrt2, +\sqrt 3i, -\sqrt3i$
$x^4+x^2-6=0$ $(x^2+3)(x^2-2)=0$ Either $x^2+3=0$ giving $x = +\sqrt 3i, -\sqrt3i$ or $x^2-2=0$ giving $x = +\sqrt 2, -\sqrt2$