How to Graph Absolute Value on a TI-84 Graphing Calculator
4.
Let’s graph the equation
y = |x + 3| . The variable x is
found under the MODE key.
Type in “x + 3”. Close the
parenthesis when you are
finished (a good habit to get
into). Then press enter.
1.
Press the y= button in
the upper left corner.
2.
Press the Math button.
Your screen should look like
this.
3.
Press the arrow key once
to move over to the NUM menu.
Then press enter.
5.
Your calculator will
now graph the absolute value
function. Press the TRACE
button and the calculator will
also give you the equation of
the graph and the y intercept.
6.
By pressing the arrow keys you can
move the cursor to the approximate vertex of
the graph. Note the x and y coordinates are
given, but these are only approximations. To
find the exam coordinates of the vertex, use
the –b/a + c formula; in this case it would be
-3/1 = > (-3,0).
7.
Tip: when you are graphing a negative
function such as y = - |x + 3| be careful NOT
to use the subtraction key – you will get an
error message. Instead use the negative key at
the bottom right of the calculator.
NO!
YES!