If a parabola opens up, the vertex is the lowest point on the graph, hence it has a minimum value.
If a parabola opens down, the vertex represents the highest point on the graph, hence we can say it has a maximum value.
The range of a graph is the set of all possible y-values.
• If a parabola has a maximum value, that means it opens down. Since it opnes down, the range of the parabola will be all outputs, ,less than, that maximum value.
The parabola above has a maximum at y = 10.
The range of the graph will be all outputs less than 10(maximum value).
Therefore, if a parabola has a maximum value then the range will be all outputs less than that maximum value.
• If a parabola has a minimum value, that means it opens up. Since it opens up, all set of possible y-values will be greater than the minimum value.
Therefore, if a parabola has a minimum value then the range will be all outputs greater than the minimum value.
ANSWER:
• Less than.
,• Greater than
