The axis of symmetry is a vertical line that divides a graph into two symmetric halves.
- On the left side of the axis of symmetry, as time increases, the height generally decreases if the function represents a downward-opening curve like a parabola or an exponential decay function. If the function represents an upward-opening curve like a cubic function, the height generally increases as time increases on the left side of the axis.
- On the right side of the axis of symmetry, the trend is typically opposite to the left side. If the function represents a downward-opening curve, the height generally increases as time increases on the right side of the axis. Conversely, if the function represents an upward-opening curve, the height generally decreases as time increases on the right side of the axis.
