Answer:
3rd option: f(x) = (x +
)² +
Explanation:
find the x-coordinate of the vertex for 'x² + x + 1' using: -b/2a
a = 1
b = 1
c = 1
-1/2(1) = -1/2
now find the y-coordinate of the vertex by plugging in -1/2 for 'x'
= (-1/2)² + (-1/2) + 1 = 1/4 - 2/4 + 4/4 = -1/4 + 4/4 = 3/4
now you know that the vertex is at (-1/2, 3/4) and you can make your selection