Help please.

3rd option:  f(x) = (x + )² +

Step-by-step 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