To CAS, or not to CAS? That is the question.

When you buy a modern calculator, one of the first things you'll have to consider is whether to go with a slightly more expensive CAS model, or stick with the base model. Well, to make this decision, you will need to take a few things into consideration.

First, what is CAS? Well, this acronym stands for Computer Algebra System. In a very basic sense, this system allows the calculator to recognize non-numerical symbols, and solve algebra for you. Pretty sweet, huh?

So, as a student, this feature might be of great benefit to you. Let's say you're a student and you are given a formula and a problem. With a CAS calculator, you can type the formula directly into the calculator, specify the variable(s), and it will solve it for you. The system can pretty much tackle anything you will encounter as a student including polynomials in multiple variables; standard functions of expressions (sine, exponential, etc.); various special functions (Γ, ζ, erf, Bessel functions, etc.); arbitrary functions of expressions; optimization; derivatives, integrals, simplifications, sums, and products of expressions; truncated series with expressions as coefficients, matrices of expressions, and Numeric domains supported typically include real, complex, interval, rational, and algebraic.

So how does this magical feature work? Here are a few simple steps to get you going. Keep in mind I'm on a Texas Instruments Nspire CX CAS.

Lets say this is your problem:
Side A of a triangle is 7 feet, and the hypotenuse is 15 feet. What is side B?

First, you're going to open up the calculator program, and hit the 'menu' button. Then select "Algebra."

Next, select the sixth option called "Numerical Solve."

In the parenthesis, start to enter your equation. In this case it would look like this: nSolve(7² +b² =15²)

Now define the variable. Add a comma, and then the variable you used. nSolve(7² +b² =15²,b)

Hit enter, and if you did everything right, it will spit out the length of side B; 13.27 feet.

As you can see, I simply used the letter keys to enter the variable 'b,' and for the equals sign, I used the equals symbol button at the top left of the keypad, NOT the enter button. Remember to keep the entire equation inside the parenthesis, and to define your variables with a comma, then the variable you used.

So, if it were my choice, I would say go with a CAS calculator. As a student it simplifies my work, and saves me a lot of written work that you would have to do with a more basic calculator. CAS enabled devices usually cost a bit more than their counterpart as well. The choice is yours!