Question

Relsova em R
A)x4 -10x² + 9 = 0

Answer 1

Resposta:

x = ± 1 e x = ± 3

Explicação passo-a-passo:

$x^4 - 10x^2 + 9 = 0 \\\ (x^2)^2 - 10(x^2) + 9 = 0 \\\ x^2 = a \\\ a^2 - 10a + 9 = 0 \\\ \Delta = (- 10)^2 - 4.1.9 \\\ \Delta = 100 - 36 \\\ \Delta = 64 \\\ \sqrt{64} = \pm 8 \\\ a' = \frac{- (- 10) + 8}{2.1} \\\\\ a' = 9 \\\ a" = \frac{- (- 10) - 8}{2.1} \\\\\ a" = 1 \\\ x^2 = a \\\ x = \pm \sqrt{a} \\\ x' = \pm \sqrt{9} \\\ x' = \pm 3 \\\ x" = \pm \sqrt{1} \\\ x" = \pm 1$

Espero ter ajudado.