Determine the vertex of the graph of the parabola.
-$y = x ^ { 2 } - 2 x - 8$
A)(- 1, - 9)
B)(1, - 9)
C)(1, 9)
D)(- 1, 9)

Question

Quizplus · Accepted Answer

The vertex of a parabola in the form $y = ax^2 + bx + c$ can be found using the formula $(-b/2a, f(-b/2a))$. For $y = x^2 - 2x - 8$, $a = 1$, $b = -2$, and $c = -8$. Thus, the x-coordinate of the vertex is $-(-2)/(2*1) = 1$. Plugging $x = 1$ back into the equation gives $y = 1^2 - 2*1 - 8 = -9$. Therefore, the vertex is $(1, -9)$.

Determine the Vertex of the Graph of the Parabola y=x2−2x−8y = x ^ { 2 } - 2 x - 8y=x2−2x−8

Determine the Vertex of the Graph of the Parabola $y = x ^ { 2 } - 2 x - 8$