## College Algebra (10th Edition)

$x=\pm 1$
We solve by factoring: $3x^{4}-2x^{2}-1=0$ $(3x^{2}+1)(x^{2}-1)=0$ $3x^{2}+1=0$ or $x^{2}-1=0$ $3x^{2}=-1$ or $x^{2}=1$ $x^2=\frac{-1}{3}$ or $x=\pm\sqrt{1}$ $x=\pm \sqrt{\frac{-1}{3}}$=not real or $x=\pm 1$ $x=\pm 1$ We ignore the unreal solution.