Answer:
Vertex is (-1, -9)
Step-by-step explanation:
To find the x-value of the vertex, we use the formula
x
=
−
b
2
a
(This is considered the axis of symmetry).
a
=
1
and
b
=
2
with
c
=
−
8
(These are the numbers in order)
By substituting we get
x
=
−
(
2
)
2
⋅
1
, which simplifies to
x
=
−
1
.
Once you find x, substitute back into the equation to find y.
y
=
(
−
1
)
2
+
2
(
−
1
)
−
8
y
=
1
−
2
−
8
y
=
−
9
Putting the two numbers together you get the coordinates
(
−
1
,
−
9
)
.
