3
advanced-math

Find the vertex of y=x28x+12y = x^2 - 8x + 12.

A

(4,4)(4, -4)

B

(4,60)(-4, 60)

C

(4,4)(4, 4)

D

(4,4)(-4, -4)

Correct Answer: A

Choice A is the correct answer. The x-coordinate of the vertex is given by h=b/2ah = -b/2a.

  1. Identify: a=1,b=8a=1, b=-8.
  2. Calculate h: h=(8)/2(1)=8/2=4h = -(-8) / 2(1) = 8 / 2 = 4.
  3. Calculate k: Substitute x=4x=4 back into the equation. y=428(4)+12=1632+12=4y = 4^2 - 8(4) + 12 = 16 - 32 + 12 = -4.

So the vertex is (4,4)(4, -4).

Choice B is incorrect because it uses x=4x=-4. Choice C is incorrect because of a sign error in calculation (1632+12eq416-32+12 eq 4). Choice D is incorrect because it uses x=4x=-4.