I currently have a Ti-83 which I’ve had since middle school and while I do love it, I’m thinking about upgrading or trying out a new calculator. I heard the Ti-89 and HP 50g are really popular ones that are much more powerful. I was wondering could anyone who is an engineering or math related major, or anyone that has experience, explain some differences between these calculators? What can I do on the Ti-89 or HP 50g that I can’t on a Ti-83?
Thanks and your help is really appreciated!
To add: Also if it helps I’m a civil engineering major so I’ve either already or am going to be taking a lot of upper math, DiffEq, Linear Algebra, physics, statics, structural, fluid, and design related courses.
The biggest advantage of a TI-89 is that it has a CAS system, i.e. it can solve symbolic algebra expressions. That means it can solve for one variable in a difficult expression, perform indefinite integrals and derivatives, etc. Very useful tool for exams when you are allowed to use it; gets rid of many idiotic mistakes that just come with the business. Never used a HP 50g.
I used both; each had their own merits. If you have the money, the TI-89 is definitely worth using. Once you get over the initial difficulty involved in understanding how it works, it’s a very useful tool that works a lot better than the 83.
I have always used HP calculators as I really like using the RPN system. Never used the 50g, but it looks like it does a lot and will also do algebraic inputting as well as RPN.
However, a calculator is limited in what it can do. You may want to learn how to use Mathcad instead. It is a PC based program that can be described as “an engineers notepad”. You can see all your calculations and save the worksheets for future reference. Much more powerful. A student version is available for around $100. Your school may even have it available. It is also used in many companies, so you will be learning a program that you will use in your professional career.
Speed is the name of the game in my opinion and I have yet to find anyone with an 83 or 89 who can beat me in terms of getting the answer vs my ti-36x pro. It has a ridiculous amount of built-in capabilities and has served me well for any course that has allowed or required a calculator. That said, I used an 89 for solving larger/more complicated matrices in linear algebra ( i.e. 6x6) and electric circuits (i.e. 3x3 with complex conjugates) and any exam where it was quicker to solve for min/max using the graph or just to see the graph. Out of 27 math/science/engineering courses so far I can almost count on one hand the number of exams where a graphing calculator was required/more useful. The 89 is also the best for speed in expanding/factoring polynomials (useful in DiffEq). After a certain point it makes more sense to do assignments with MATLAB and/or EES rather than fiddle with a graphing calculator.
As a CivE keep in mind your FE exam for which the ti-36x is the most powerful calculator allowed, so you want to get intimately familiar with it now.
@HPuck35 I was wondering what exactly does RPN do. I looked it up and it seems to relate to Pemdas but I’m not completely clear on how it works?
@da6onet I’m actually taking DiffEq next semester so this actually sounds pretty useful. I’ll definitely look into grabbing the ti-36x down the road for the FE too, thanks for your advice!
RPN is “Reverse Polish Notation”. How it got to be called that is unknown to me. Probably a backhanded comment.
Algebraic input is just like the equation reads; (7+3)*12=
Entering the same expression in RPN would be: 7, enter, 3, +, 12, *
Although the RPN way of doing calculations looks crazy, it does force you to look at the relationships of the numbers in the expression and you do get to see the intermediate results as you are performing the calculation. I find that knowing the relative values of some of the intermediate results valuable in understanding what is going on in the expression (and therefore the physical problem you are working on). Algebraic input does not provide any intermediate results and you don’t get any feel as to the relative magnitude of the individual parts of any longer calculations.
In the above example, after you enter the + sign when using RPN, you will see that the value within the parentheses is 10.
Think of RPN as a stack of numbers (typically 4 numbers) that you are entering numbers on the bottom of the stack and when you enter a operator, you are telling what it is to do with the bottom 2 numbers in the stack. (kind of hard to explain in words but showing the stack after each input makes it clear)
I know many engineers that use HP calculators for the RPN way of doing calculations. I can’t think of (off the top of my head that is) a single non-engineer that uses RPN. Don’t really know what that means.
Make sure you get a CAS version if you go Ti 
Yup, outside of engineering I know there are tons of people that brag that they got by fine with their 83/84 and that an 89 is not necessary, but it is very advantageous for electrical engineering (you’re Civil, but I’m sure auto solving DEs would help still).
Automatic Laplace and inverse Laplace transforms, maybe I can put Fourier on there… Speeds up complex (imaginary) calculations and equations. ~Lower division classes Ti-89 is less common than the Ti-83/84, upper division, the 89 or the N-spire with CAS is in the hands of almost every student.