Question

Given: y=x^2-4x-12

A.) determine the roots/zero
(By factoring & setting the answer equal to zero)

B.) use h=-b/2a to get vertex

Answer 1

x = -2, 6

Vertex: (2,-16)

Explanation:

x² - 4x - 12

x² - 6x + 2x - 12

x(x - 6) + 2(x - 6)

(x - 6)(x + 2) = 0

x = -2, 6

h = -(-4)/2

h = 4/2

h = 2

k = 2² - 4(2) - 12

k = 4 - 8 - 12

k = -16

Vertex: (2,-16)

Answer 2

see below

Explanation:

y=x^2-4x-12

Set equal to 0 to find the zeros

0 =x^2-4x-12

Factor. What 2 numbers multiply to -12 and add to -4

-6*2 = -12

-6+2 = -4

0= (x-6) (x+2)

Using the zero product property

0=x-6 0 = x+2

x=6 x = -2

zeros: -2,6

Vertex

h = -b/2a = - (-4)/ 2(1) = 4/2 = 2

OR Average the roots (-2+6)/2 = 4/2 =2

The y coordinate is found by substituting into the equation

y = (2)^2 -4(2) -12

y = 4-8-12

y =-16

vertex : (2, -16)