Question

ACHE O VALOR DE DELTA E DO X


– x² + x + 2 = 0

Answer 1

– x² + x + 2 = 0  . ( - 1 )

x² - x - 2 = 0

Δ = b² - 4 . a . c

Δ = ( - 1 )² - 4 . 1 . - 2

Δ = 1 + 8

Δ = 9

x = - b ± √ Δ

         2 . a

x = - ( - 1 ) ± √9

            2 . 1

x = 1 ± 3

       2

$x' = \frac{1 - 3}{2}$

$x' = \frac{- 2}{2}$

x' = - 1

$x'' =\frac{1 + 3}{2}$

$x'' = \frac{4}{2}$

x'' = 2

S = { - 1, 2 }