Respuesta :
Answer:
(2, -32)
Step-by-step explanation:
1) Expand them.
y = 2(x² - 6x + 2x - 12)
y = 2(x² - 4x - 12)
y = 2x² - 8x - 24.
2) Complete the square to find the vertex.
y = 2([x² - 4x)] - 24
y = 2[(x - 2)² - 4] - 24
y = 2(x - 2)² - 8 - 24
y = 2(x - 2)² - 32
The vertex: (2, -32)
or you can use this: x = -b/2a
x = -(-8)/2(2)
x = 8/4
x = 2
Substitute the value into the original equation for y.
y = 2(2)² - 8(2) - 24
y = 2(4) - 16 - 24
y = 8 - 16 - 24
y = -32
Vertex: (2, -32)
Answer:
(2, -32)
Step-by-step explanation:
The vertex of the graph of a quadratic equation is on the line of symmetry, halfway between the x-intercepts. It can be found by evaluating the equation at that point.
Line of symmetry
The given function is written in factored form, so the x-intercepts are easy to find. They are the values of x that make the factors zero:
(x +2) = 0 ⇒ x = -2
(x -6) = 0 ⇒ x = 6
The midpoint between these values of x is their average:
x = (-2 +6)/2 = 4/2
Then the x-coordinate of the vertex, and the equation of the line of symmetry is ...
x = 2
Vertex
Using this value of x in the quadratic relation, we find the y-value at the vertex to be ...
y = 2(2 +2)(2 -6) = 2(4)(-4)
y = -32
The coordinates of the vertex are (x, y) = (2, -32).
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