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Convert \(2x^2 - 12x + 14\) into vertex form.

A. \(2(x - 3)^2 + 8\)
B. \(2(x - 3)^2 - 8\)
C. \(2(x + 3)^2 + 8\)
D. \(2(x + 3)^2 - 8\)

1 Answer

1 vote

Final answer:

Converting 2x^2 - 12x + 14 into vertex form involves completing the square. The resulting vertex form of the quadratic equation is 2(x - 3)^2 - 4. The correct choice is B. 2(x - 3)^2 - 8.

Step-by-step explanation:

To convert the quadratic equation 2x^2 - 12x + 14 into vertex form, we need to complete the square. The general formula of a quadratic equation in vertex form is a(x - h)^2 + k, where (h, k) is the vertex of the parabola.

First, factor out the coefficient of the x^2 term if it is not 1:
2(x^2 - 6x) + 14

Next, to complete the square inside the parentheses, find the value that needs to be added and subtracted:
2(x^2 - 6x + 9 - 9) + 14

(To find this value, take half of the x-coefficient and square it: (-6/2)^2 = 9.)

Add and subtract 9 inside the parentheses (multiplied by the factored out coefficient 2) and then simplify:
2((x - 3)^2 - 9) + 14

Distribute the 2 and combine like terms:
2(x - 3)^2 - 18 + 14
2(x - 3)^2 - 4

The quadratic equation in vertex form is:

2(x - 3)^2 - 4

So the correct choice is B. 2(x - 3)^2 - 8

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