Automatic Simplification - Texas Instruments TI-89 Titanium User Manual

In the AUTO setting, functions such as
exactly, and then use approximate numerical methods if necessary to determine
additional solutions. Similarly, ä (integrate) uses approximate numerical methods if
appropriate where exact symbolic methods fail.
Advantages
You see exact results when practical,
and approximate numeric results
when exact results are impractical.
You can often control the format of a
result by choosing to enter some
coefficients as either rational or
floating-point numbers.

Automatic Simplification

When you type an expression on the entry line and press ¸, the TI-89 Titanium
automatically simplifies the expression according to its default simplification rules.
Symbolic Manipulation
determine as many solutions as possible
solve
Disadvantages
If you are interested only in exact
results, some time may be wasted
seeking approximate results.
If you are interested only in
approximate results, some time may
be wasted seeking exact results.
Moreover, you might exhaust the
memory seeking those exact results.
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