Question

Encontre as raízes de
x^4 - 6x^2 +9 = 0

Answer 1

$x^4 - 6x^2 +9 = 0\\ \\ \boxed{y=x^2}\\ \\ y^2-6y+9=0\\ \\ \Delta=(-6)^2-4.1.9=36-36=0\\ \\ y=\frac{6}{2}=3\\ \\ Logo \ x^2=3\\ \\ \boxed{x=\pm \sqrt3}$