Finding the Coordinates of the Vertices in the Feasible Region
Using the Graphing Calculator
Directions: Follow the step by step instructions below in order to graph the feasible
region for the following system of inequalities and find the coordinates of the
vertices using the TI-83 Graphing Calculator.
Y≥0
X≥0
Y ≤ 1/2x + 2
Y ≤ -x + 7
1. Press the “y =” key on your calculator. If there are already equations in here
clear them all out.
2. Enter each function which contains a “y”.
3. Use the left arrow to move cursor to the \ symbol.
4. Press enter repeatedly to scroll through the different options.
Choose the appropriate type of shading (above or below the boundary
line), remembering that we are shading the NON-solution area.
5. Press “graph” to view your graph. Keep in mind that you have the
added constraint of x ≥ 0 which is not shown on the graph.
6. Find the coordinates of each vertex of the feasible region. When the
vertex is formed by the intersection of two functions, the calculator
can determine the coordinate of the point of intersection using the
following steps:
a) Choose CALC (2nd, TRACE)
b) From the CALCULATE menu, choose 5: intersect
c) You will be brought to the graph screen, and asked for the first
curve. Use the up and down arrows to place the cursor on one of
the functions and press enter.
d) You will be asked for the second curve. Select it in the same way
and press enter.
e) You will be asked for a guess. Move the cursor to where it looks
like the graphs are intersecting (this is your guess at the
coordinate) and press enter. The coordinates of the intersection
will be displayed at the bottom of the screen.
7. You can find the values of the vertices which occur on the line x = 0
simply by reading the graph.
Record the coordinates of each vertex below.
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