Answer:
Option A: Axis of symmetry: x = -0.5; Vertex: (-0.5, 0.75); f(x) = x2 + x + 1
Step-by-step explanation:
1) The axis of symmetry of quadratic graph is the vertical line that divides the graph curve into two congruent halves. In this case, it is: x = -0.5
2) Vertex is the point at which the graph curve changes direction or simply coordinates of the crest or trough of the curve.
The graph given has a trough with the coordinates: x = -0.5, y = 0.75. This is (-0.5, 0.75)
3) The roots of a quadratic equation are the points where the curve crosses the x-axis. In this case, it doesn't cross and so we have imaginary roots.
Now, formula for line of symmetry is; x = -b/2a
Thus; -b/2a = -0.5 or -b/2a = -1/2
Thus, b = 1 and a = 1
Our first and second terms will now be;
x² + x
Looking at the options, the only one with x² + x as it's first 2 terms is option A.
Thus, the complete equation will be x² + x + 1
