Standard Form:
The standard form of a quadratic function is: ax2 + bx + c,
where a ≠ 0, and a, b and c are positive numbers.
The graph of a quadratic equation is a parabola. The graphs can be upward or downward.
y = -2x2 - 3x - 4 (upward)
y = - x2 + 3x - 2 (downward)
The vertex of the upward parabola above is the lowest point (2, - 3), called the minimum.
The parabola has a property called symmetry, which means the parabola can be folded in half so that each half matches the other exactly. The fold line is called the axis of symmetry. In the above parabola, the fold line is the dotted line, x = 2.
In the above downward parabola, the vertex is the maximum point, (- 1, 3), and the axis of symmetry is x = -1
The equation for the axis of symmetry for a quadratic function is:
x = - b/2a
