Question

Qual é a raiz de y= -x elevado a 2 x + 15

Answer 1

Bom dia.

y = -x² + 2x + 15

∆ = -b² - 4 . a . c

∆ = (-2)² - 4 . (-4) . 15

∆ = 4 + 60

∆ = 64

x = -b ±√Δ / 2 . a

x = -2 ± √64 / 2 . (-1)

x = -2 ± 8 / -2

x1 = -2 + 8/-2 = 6/-2 = -3

x2 = -2 - 8/-2 = 10/2 = 5

S { -3 , 5 }