Question

2×
$2 {x}^{4} - 4 {x}^{2} - 6 = 0$
-4×2-6=0​

Answer 1

número não e Real x € r

Answer 2

$2 {x}^{4} - 4 {x}^{2} - 6 = 0 \div 2 \\ {x}^{4} - 2 {x}^{2} - 3 = 0$

${ {(x}^{2}) }^{2} - 2 {x}^{2} - 3 = 0$

faça x²=k

${k}^{2} - 2k - 3 = 0 \\ k= \frac{ - ( - 2) ± \sqrt{ {( - 2)}^{2} - 4.1.( - 3) } }{2.1}$

$k = \frac{2 ± \sqrt{4 + 12} }{2} \\ k = \frac{2 ± \sqrt{16} }{2} \\ k = \frac{2 ±4 }{2}$

$k = \frac{2 + 4 }{2} = \frac{6}{2} = 3$

${x}^{2} = k \\ {x}^{2} = 3 \\ x = ± \sqrt{3}$

S={-√3,√3}