Question

1) f(x) = x2 - 7x + 12
2) f(x) = x2 – x – 2
3) f(x) = x2 + 4x + 3
4) f(x) = x2 – 2 x – 8
urgente ​

Answer 1

Explicação passo a passo:

Para calcular as raizes utilizamos a fórmula de bhaskara

Δ = b² – 4.a.c

1) f(x) = x² -7x + 12           a=1; b = -7; c = 12

Δ = 49 - 4 . 1 . 12

Δ = 1

x = (– b ± √Δ)

/2a

x = 7 ± 1/2

x1 = 4   x2 = 3

2) f(x) = x² -x -2       a=1; b = -1; c = -2

Δ = 1 - 4 . 1 . -2

Δ = 9

x = (– b ± √Δ)

/2a

x = 1 ± 3/2

x1 = 2    x2= -1

3) f(x) = x² +4x + 3   a=1; b = 4; c = 3

Δ = 16 - 4 . 1 . 3

Δ = 4

x = (– b ± √Δ)

/2a

x = -4 ± 2/2

x1 = -1  x2= -3

4) x² -2x -8   a=1; b = -2; c = -8

Δ = 4 - 4 . 1 . -8

Δ = 36

x = (– b ± √Δ)

/2a

x = 2 ± 6/2

x1= 4   x2= -2