ian9614's Full Review: Hewlett Packard 48gx Graphic Calculator
I've wrote a few reviews over products, but I must say that the HP 48GX is one of the best purchases I've made. I'm sure that you've probably read some other reviews and know by now that this is not the easiest calculator to learn, but it is well worth the time invested. I won't go into what the calculator can and cannot do (you can read that on the HP site), but I will say that unless you design stealth bombers, this calculator will most likely compute any function you will ever need to evaluate. I have a semester left until I get my electrical engineering degree, and the HP has never let me down. I've never encountered a function that I needed, and was not there.
Layout of the 48 is logical, and functions are easy to remember. I've compared my calculator with other higher-end TI models (the HP's only real rival) and I've found that functions are harder to recall, that there are more steps to go through from the time a user starts with an input until the time the user gets final output. This is especially true when evaluating a large amount of numbers.
Reverse Polish Notation (RPN) is applied in this calculator, and I'd say that the majority of the learning problems are from this type of input. RPN can be explained in an example. First, say that you want to add the four numbers 2, 4, 3, and 9. On a standard input calculator your input would be 2 function +, 4. This would give you an answer of 6. Next you would enter function +, 3. This would give an answer of 9. Finally, you would enter function +, 9. This would give a final answer of 18. Easy enough.
On the 48, where RPN is implemented, the data entered is stored in a "stack". These stacks are similar to windows on a computer, where data can be entered one line at a time. This is the process you would go through to get the same result as above. Number two button, ENTER. Number four button, ENTER. Number three button, ENTER. Number 9 button, enter. Function +, Function +, Function +. This may seem weird at first, it certainly did to me, but for large amount of numbers, such as averages for teachers (or students) this process is MUCH easier and has a MUCH higher lack of errors than the standard manner. Multiplication, Division, and all other functions are performed this way. The big deal? DATA FROM THE PREVIOUS APPLICATION IS STORED ABOVE THE CURRENT FUNCTION. This saves much time from writing answers for later use, since all your data is stored in the lines above what you are doing!
Other great ideas incorporated into this calculator are; Hard-memory-saved equation library, every unit that you could ever need (both in SI and standard), unit conversion (from SI to standard), EQUATION WRITER (very useful), 128K ram (way more than I've ever needed), of course, graphing, ARC (sin, cos, tan) keys, standard step-through wizards for key operations (Differentiation, integration, exc..), ability to write equations as you would write them, instead of the confusing and time consuming "computer fashion"....you know.... ((4X^3)/(9*X^6))/7X!.
This calculator is sturdy. I've dropped it numerous times, and it's still ticking. It has a clock, along with date,month,year. Programmable alarm. A game for those boring lectures, and the GX has a slot for expansion. Many cards are available for this calculator, such as memory expansion, formula tables, applications for certain fields (like surveying), tutorial cards for subjects like trig, cal, alg (Don't ask me where, I saw them a long time ago, but I know they exist!). Just about anything you could want or need. But, and this is a big but, you probably won't use this expansion slot. I don't. Never have. Never needed too. And if you don't think that you will need it, just get the 48 G, and save yourself one hundred dollars. I bought the 48 GX, and for two hundred dollars, it's been worth every penny. If you are a professional, in college, or mid-hs planning on going to college, you owe it to yourself to buy this. You'll hate it at first, but after you learn it, you'll absolutely love it. And your instructors won't know how to clear your calculator's memory. Hell, even you won't! :)
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