Question

Suppose you were to graph a parabola given by the equation y=14x2+3x−1
𝑦
=
1
4
𝑥
2
+
3
𝑥
−
1
. Which ordered pair would be the vertex of the graph?(1 point)
Responses

(−6,−11)
(
−
6
,
−
11
)

left parenthesis negative 6 comma negative 11 right parenthesis

(−6,−9)
(
−
6
,
−
9
)

left parenthesis negative 6 comma negative 9 right parenthesis

(−6,−1)
(
−
6
,
−
1
)

left parenthesis negative 6 comma negative 1 right parenthesis

(−6,−10)
(
−
6
,
−
10
)

left parenthesis negative 6 comma negative 10 right parenthesis

Answer 1

Use the vertex formula x = -b/(2a). Here a = 1/4 and b = 3, so x = -3/(2·(1/4)) = -3/(1/2) = -6.
Plug in x = -6: y = (1/4)(36) + 3(−6) − 1 = 9 − 18 − 1 = −10.

Vertex: (−6, −10).