Operation Manual

Chapter 3: Function Graphing 80
Displaying the Window Variables
To display the current window variable values, press p. The window editor above and to the right
shows the default values in Func graphing mode and Radian angle mode. The window variables differ
from one graphing mode to another.
Xres sets pixel resolution (1 through 8) for function graphs only. The default is 1.
•At
Xres=1, functions are evaluated and graphed at each graphed pixel on the x-axis.
•At Xres=8, functions are evaluated and graphed at every eighth graphed pixel along the x-axis.
Note: Small Xres values improve graph resolution but may cause the graphing calculator to draw
graphs more slowly.
Changing a Window Variable Value
To change a window variable value from the window editor, follow these steps.
1. Press † or } to move the cursor to the window variable you want to change.
2. Edit the value, which can be an expression.
• Enter a new value, which clears the original value.
• Move the cursor to a specific digit, and then edit it.
3. Press Í, †, or }. If you entered an expression, the TI-84 Plus C evaluates it. The new value is
stored.
Note:
Xmin<Xmax and Ymin<Ymax must be true in order to graph.
Storing to a Window Variable from the Home Screen or a Program
To store a value, which can be an expression, to a window variable, begin on a blank line and follow
these steps.
1. Enter the value you want to store.
2. Press ¿.
3. Press  to display the
VARS menu.
4. Select
1:Window to display the Func window variables (X/Y secondary menu).
• Press ~ to display the Par and Pol window variables (T/q secondary menu).
• Press ~ ~ to display the Seq window variables (U/V/W secondary menu).
5. Select the window variable to which you want to store a value. The name of the variable is pasted
to the current cursor location.
6. Press Í to complete the instruction.
When the instruction is executed, the TI-84 Plus C stores the value to the window variable and displays
the value.
@X and @Y
The variables @X and @Y (items 8 and 9 on the VARS (1:Window) X/Y secondary menu; @X is also on the
Window screen) define the distance from the center of one pixel to the center of any adjacent pixel on
a graph (graphing accuracy). @
X and @Y are calculated from Xmin, Xmax, Ymin, and Ymax when you
display a graph. In Func graphing mode, TraceStep and @X are related as shown in the table below.