WAEC Further Mathematics 2010 Paper

Concept:The axis of symmetry of a quadratic curve is a vertical line that divides the parabola into two mirror images. For $y = ax^{2} + bx + c$, it is given by $x = -\frac{b}{2a}$.Explanation:The given curve is $y = x^{2} - 4x - 12$.Rewrite it in standard form: $y = 1 \cdot x^{2} + (-4)x + (-12)$.Thus, comparing with $y = ax^{2} + bx + c$, we get $a = 1$, $b = -4$, and $c = -12$.Use the formula for the axis of symmetry: $x = -\frac{b}{2a}$.Substitute the values: $x = -\frac{-4}{2(1)}$.Simplify step by step: $x = \frac{4}{2}$.Therefore, $x = 2$.This is the vertical line of symmetry of the parabola.Answer:The axis of symmetry of the curve is $x = 2$.This matches option C.