Solution 12101: Limit() Function Returns Unexpected Answers on the TI-89 Family, TI-92 Family, or Voyage™ 200 Graphing Calculators.
Why does the limit() function sometimes return unexpected answers in approximate mode on the TI-89 family, TI-92 Family, or Voyage 200 graphing calculators?
The limit() function is very sensitive to round off errors in floating point (decimal) numbers -- especially near removable or unremovable singularities. It is suggested to avoid floating-point constants and APPROXIMATE mode when using the limit() function. Try all problems in EXACT or AUTO mode for better results.
Please see the TI-89 family, TI-92 family and Voyage 200 guidebooks for additional information.