Question

2x² – 4x – 1 = 0 determine a raiz

Answer 1

Resposta:

2x² – 4x – 1 = 0

a= 2

b= -4

c = -1

Δ = b² - 4 * a * c

Δ = (-4)² -4 * 2 * -1

Δ = 16 + 8

Δ = 24

-b +- √Δ     /2 * a

- (-4) +- √24     /2 *2

4 +- 4,89897948557    / 4

x' = 4 + 4,89897948557    / 4

x' = 8,89897948557 / 4

x' = 2,22474487139    ou 2,22

x" = 4 - 4,89897948557    / 4

x" = -0,89897948556 /4

x" = -0.22474487139     ou -0,22

Resposta : S{ 2,22  e -0,22 }

Answer 2

X= -(-4)±√(-4)²-4×2×(-1)

________________

2×2

X= 4±√16+8

_______

4

X= 4±√24

______

X= 4 ±2 √6

______. (simplifique o 4 de cima com o de baixo)

4

X1= 2-√6

_____

2

x2= 2+√6

_____

2