Operation Manual

Appendix B: Reference Information 392
Accuracy Information
Computational Accuracy
To maximize accuracy, the TI-84 Plus C carries more digits internally than it displays. Values are stored in
memory using up to 14 digits with a two-digit exponent.
• You can store a value in the window variables using up to 10 digits (12 for
Xscl, Yscl, Tstep, and
q
step).
• Displayed values are rounded as specified by the mode setting with a maximum of 10 digits and a
two-digit exponent.
•
RegEQ displays up to 14 digits in Float mode. Using a fixed-decimal setting other than Float causes
RegEQ results to be rounded and stored with the specified number of decimal places.
Xmin is the center of the left most pixel, and Xmax is the center of the next to the right most pixel of
the graph area. (The right most pixel is reserved for the busy indicator.) @
X is the distance between the
centers of two adjacent pixels.
Ymin is the center of the next to the bottom pixel; Ymax is the center of the top pixel of the graph
area. @
Y is the distance between the centers of two adjacent pixels.
VERSION
You have attempted to receive an incompatible variable version from
another graphing calculator.
A program may contain commands not supported in the OS version on
your graphing calculator. Always use the latest OS. TI-84 Plus C and
TI-84 Plus share programs but a version error will be given if any new
TI-84 Plus C programs may need to be adjusted for the high resolution
graph area.
WINDOW RANGE
A problem exists with the window variables.
• You defined Xmax  Xmin or Ymax  Ymin.
• You defined q
max qmin and qstep > 0 (or vice versa).
• You attempted to define
Tste p = 0.
• You defined Tmax  Tmin and Tstep > 0 (or vice versa).
• Window variables are too small or too large to graph correctly. You
may have attempted to zoom in or zoom out to a point that exceeds
the TI-84 Plus C’s numerical range.
ZOOM
• A point or a line, instead of a box, is defined in ZBox.
•A ZOOM operation returned a math error.
Screen MODE
Full
(Xmax-Xmin) / 264 = @X
(Ymax-Ymin) / 164 = @Y
@X É… 2 = TraceStep (Function Mode)
Entering a value for @X or @Y from the home screen on a program gives:
Xmax = Xmin + @X * 264
Ymax = Ymin + @Y * 164
Error Type Possible Causes and Suggested Remedies