Answer:
Vertex: (-1,-9)
Step-by-step explanation:
The vertex of an up-down facing parabola of the form y=ax^2+bx+c is x=-b/2a
Plug the values into the equation
a=1, b=2, c=-8
x=-2/(2*1)
Simplify
x=-1
Plug in x=-1 to find the y value
y=1(-1)^2 + 2(-1) + (-8)
y= -9
Then put them in a coordinate pair
Vertex: (-1,-9)