Question

g(x)= x² + 2x

h(x)= x² -2x – 2
i(x)= 2x² +2x -1

BHASCARA DISSO

Answer 1

a)

g(x) = x^2 + 2x

a = 1

b = 2

c = 0

b^2 - 4.a.c = (2)^2 + 4.1.0 = 4 + 0 = delta

-b (+-) raiz de delta / 2.a

-2 (+-) raiz de 4 / 2.1 = -2 (+-) 2 / 2

x1 = -2 + 2 / 2 = 0

x2 = -2 -2 / 2 = -2

raízes/zeros dessa função {0,2}

b)

h(x) = x^2 - 2x - 2

a = 1

b = -2

c = -2

b^2 - 4.a.c = (-2)^2 - 4.(1).(-2) = 4 + 8 = 12 = delta

-b (+-) raiz de delta / 2.a = -(-2) (+-) raiz de 12 / 2.1 | raiz de 12 = 2 raiz de 3

2 (+-) 2 raiz de 3 / 2. 1

x1 = 2 + 2 raiz de 3 / 2 = 1 + raiz de 3

x2 = 2 - 2 raiz de 3 / 2 = 1 - raiz de 3

Raízes/zeros dessa função: {1+raiz de 3 ; 1-raiz de 3}

c)

i(x) = 2x^2 + 2x-1

a = 2

b = 2

c = -1

b^2 - 4.a.c = (2)^2 - 4.(2).(-1) = 4 + 8 = 12 = delta

-b (+-) raiz de delta / 2.a = -2 (+-) raiz de 12 / 2.2 | raiz de 12 = 2 raiz de 3

-2 (+-) 2 raiz de 3 / 4

x1 = -2 + 2 raiz de 3 / 4 = -1 + raiz de 3 / 2

x2 = -2 - 2 raiz de 3 / 4 = -1 - raiz de 3 / 2

Raízes/zeros dessa função: {-1+raiz de 3/2; -1-raiz de 3/2}