Respuesta :
Answer:
vertex = (- 1, - 7 )
Step-by-step explanation:
Given a parabola in standard form, f(x) = ax² + bx + c (a ≠ 0 )
Then the x- coordinate of the vertex is
[tex]x_{vertex}[/tex] = - [tex]\frac{b}{2a}[/tex]
f(x) = - x² - 2x - 8 ← is in standard form
with a = - 1 and b = - 2, then
[tex]x_{vertex}[/tex] = - [tex]\frac{-2}{-2}[/tex] = - 1
Substitute x = - 1 into f(x) for corresponding y- coordinate
f(- 1) = - (- 1)² - 2(- 1) - 8 = - 1 + 2 - 8 = - 7
vertex = (- 1, - 7 )
For a quadratic function like this, the vertices are points of symmetry.
We can use a shortcut such that:
x
=
−
b
2
a
In your case,
b
is 2 and
a
is 1. So:
−
2
2
⋅
1
=
−
1
Answer is -1
We can use a shortcut such that:
x
=
−
b
2
a
In your case,
b
is 2 and
a
is 1. So:
−
2
2
⋅
1
=
−
1
Answer is -1
