NECO 2023 · Paper 1 · Q22

Use the graph (a quadratic graph and a straight line) to answer: the equation of the line of symmetry of the quadratic graph is

The vertical scale is half the horizontal scale.

Worked solution (try it first)

A parabola is symmetrical about the vertical line through its lowest point, halfway between its roots.
The curve cuts the $x$ -axis at $-1$ and 2, so the line is at $x = \frac{-1 + 2}{2} = 0.5$ .
So the line of symmetry is $x = 0.5$ , option C.