OK: the Texas Instruments TI89. This has nearly all the features of the TI89 Titanium although it has considerably less memory. It is no longer manufactured, although it may still be available in stores. Its replacement is the TI89 Titanium.
Passable for now: the Texas Instruments TI86. If you already own this and don’t want to buy a new calculator now, you may be able to get by with it in Math 131. But you will doubtless want to step up to the TI89 Titanium when you take Calculus II (Math 132).
The main limitation of TI calculators with model numbers below 89 is their symbolic capabilities. For Math 131, you may find it useful to have a calculator that can find derivatives symbolically (not just numerically), in order to check your paperandpencil work; according to the TI web site, TI models 83 through 86 cannot do that. Later, for Math 132, you’ll surely want a calculator that can find indefinite integrals symbolically, in order to check your paperandpencil work; according to the TI web site, TI models 83 through 86 cannot do that.
If you insist upon using some other graphing scientific calculator, you do so “at your own risk”: Even if you bring along the instruction book, there is no guarantee that your instructor or TA can help you with such a calculator’s use.
