When their just beginning calculus, students often find themselves with face with a question in regards to their graphing calculator. Should they buy a CAS, or computer algebra system, calculator? If you don't understand what a CAS enabled calculator is, you won't be make an informed decision about whether or not to buy one.
A standard graphing calculator can only perform calculations involving numbers. That means it can divide, multiply, add, and subtract as well as complete far more complicated tasks such as logarithms, trigonometry functions, radicals, etc. However, a standard graphing calculator is not capable of performing operations on variables.
On the other hand, a computer algebra system enabled graphing calculator is capable of much more. It can manipulate variables such as x and y. This means it has the ability to factor polynomials, solve equations, even solve calculus functions such as derivatives without numerical limits. They are so powerful that some teachers don't allow them, and they have been banned from certain tests like the ACT. They are allowed on two really big examinations, however, the the SAT and the AP Calculus test. For many students, that's enough for them to decide they want one.
If you go to buy a CAS enabled graphing calculator, you'll want to make sure you are a well informed buyer. Texas Instruments is the most prolific manufacturer of graphing calculators available today. As such, most students will decide to buy a TI calculator. TI makes several CAS models you could consider. The the TI-89 Titanium, TI-Voyage 200, and the TI-Nspire CAS all have a computer algebra system. Since the TI-Voyage has a QWERTY keyboard, it is banned from virtually all standardized tests. This means for most students, it's a decision comparing the TI-Nspire CAS vs. TI-89 Titanium.
The TI-89 Titanium is not as modern. It has been around for over 10 years, but still feels fairly modern compared to most other calculators of that era. The TI-Nspire CAS is the latest and greatest from Texas Instruments. It's got high res display, a modern computer-like interface, and document creation. Whatever choice you make, be sure you have done your homework. These calculators cost in excess of 0 and you don't want to have regrets. Spend some time online checking out both options, see what your friends are saying, and you're sure to make a decision that will serve you well for many years to come.
