The vertex is the lowest or highest point of a parabola.
The vertex is the critical point of a parabola, where it reaches either its minimal or maximal y-value, depending on the orientation of the parabola. Your TI-83 graphing calculator can find the vertex of a graph with the maximum and minimum functions available in the CALC menu.
Instructions
1. Press the "Y =" button on the TI-83 and enter the function into the first line.
2. Press the "2nd" button, then press the "TRACE" button to bring up the "CALC" menu.
3. Move to either the "3: minimum" or "4: maximum" line, depending on whether the graph is an open-up or open-down parabola. If it is an open-up parabola (if the function has a positive leading coefficient), choose "3: minimum." If it is an open-down parabola (negative leading coefficient), choose "4: maximum." Press the "Enter" key to confirm your choice.
4. Choose a left bound of the vertex by using your cursor to move to a spot to the left of the vertex and pressing "Enter."
5. Choose a right bound of the vertex by using your cursor to move to a spot to the right of the vertex and pressing "Enter."
6. Make a guess by moving the cursor as close to the vertex as possible and pressing "Enter." The screen should display the cursor at the exact point of the vertex, giving the x- and y-coordinates of the vertex on the bottom-left and bottom-right corner of the screen.
Tags: pressing Enter, bound vertex, bound vertex using, CALC menu, coefficient choose
