HP 50g Graphing Calculator

Comments about HP 50g Graphing Calculator:

HP invented the handheld calculator and 35 years later their flagship HP50g is the best handheld available. It does symbolic math including trig and calculus. The solver lets you input the known values of an equation and solve for the unknowns, and the built-in equation library contains tons of the most common equations.

I really like the equation writer. It lets you enter a mathematical expression much the way you'd see it in a textbook. It's very similar to the equation editor in Microsoft Word.

The graphing capabilities let you visualize 2D and 3D graphs. I wish I had this in high school and college!

Although the calculator comes pre-configured in "algebraic mode" which means that you enter expressions like with most other calculators, it's infintely worthwhile to take 10 minutes to learn HP's unique "RPN" method and switch the calculator to RPN mode. When solving a complex problem with algebraic mode, you have to figure out how many parentheses to enter ahead of time, which is cumbersome and error-prone. With RPN, you never need parentheses and you solve the equation just as you would with pencil and paper, working from the inside out.

The calculator is faster than competing machines in most tests, and it has a MUCH faster CPU.

The biggest downside is the documentation. The 184 page printed "User's Manual" that comes with it is poorly organized for a first-time user and leaves many details out. If you aren't familiar with the HP 48 or 49 calculators, I suggest going right to the "Users Guide" that's on the CD. This is basically an expanded version of the User's Manual

Comments about HP 50g Graphing Calculator:

I use the product in solving all kinds of equations, doing graphs of differential equations, and some number theory.

The best thing about the HP 50g is probably its speed. It is by far the fastest graphing calculator HP has ever produced. It also has what is called "exact mode", which means that you can do fractions and equations with irrational numbers and the calculator keeps these untouched in your calculations.

The problems of the HP 50 are perhaps best explained when compared to the previous king of caluculators, the 48GX. On the 48GX, put an equation like "X=SIN(Y^2)" on the stack, follow it with the variable "Y" and then the command ISOL and it will return "Y=SQRT(ASIN(X))", which is the answer you would expect when solving for "Y".

Do the same thing with the HP50g and you get "Y=SQRT(PI-ASIN(X))*-1". Why the extra complexity? Why don't you get the answer you would get if you just solved the problem by hand?

If the HP 50 is then asked to isolate X on the solution just obtained, you get: back "X=SIN(PI-Y^2)", not the original equation. What gives?? The 48GX gives the original equation back.

Where the 50g really gets weird, however, is when the calculator is set to give the general answer to entered problems, as opposed to the primary answer (yes, HP calculators are that configurable). The 48 gives a 1-line expression containing s1, which means plus or minus 1, and n1, which represents an arbitrary integer (both of these are explained in the manual). The much-applauded HP 50g gives a list of 4 relatively complicated equations which, although MAY be technically correct, don't give the user any help at understanding the answer. Also, don't try this if you already have a "Y" variable already stored in the current directory, or you won't get an answer at all, but a message saying: "ISOL Error: No solution found".

Again, if you do get solutions and try reversing the process by isolating X back in either the principle answer or any of the 4 general solutions, you still don't get back the original equation. This just seems to be unreasonable behavior for such an expensive, flagship calculator.

How could HP have not noticed these issues? Is is simply too costly to fix the problem when most users seem not to complain about it? By the way, I am using the latest version of software available at this time, "Revision #2.15", not version 1.x. Both versions I have tried have the same problems.

Lastly, I have little appreciation for the built-in help. It only has entries for perhaps half of the built in functions, and only a few of these have concrete examples built into them. How could HP not see that a comprehensive and complete help system would add a lot of value to the calculator and shorten the learning curve significantly? Was there not enough memory to do a good job? I constantly have to refer to one of the online manuals available for advanced users when using this calculator.

Overall, I think that I would truly love this calculator if they would just fix the bugs and the missing help in the software. Could a software version 3.x be the answer? Are you listening, HP???

Comments about HP 50g Graphing Calculator:

I was hoping for a calucator of similar construction quality to the HP35 or even better the HP-15C. This one is more run of the mill and will probably not last like my 25 year old HP-15C. But the calculator does function well and has RPN, so it will at least be useful for as long as it lasts.

Comments about HP 50g Graphing Calculator:

I'm finding it's extremely hard to find websites where you can write a good review of the Hp 50g graphing calculator. And most of the reviews I've found have been rave. One customer even had a review headline that said "Is there anything it can't do?" Now that's a question you don't want to ask of Hp 50g because two months into ownership I've found a few things it cannot do. For example it won't even do something as simple as a full expansion of a product of multinomials (polynomials in several variables, say in X, Y, and Z). Its EXPAND function will only go so far as expanding only in the variable X (i.e. collect everything in terms of powers of X and by treating the other variables as fixed constants thereby grouping them into coefficients). I spent hours searching for a way around this with no results. This is frustrating since what I've described is a very basic algebraic operation which a top-of-the-line graphing calculator should be able to do. The manual was of no help at all this. By contrast, TI-89 Titanium does this with ease. It has simple commands that let you do either a full expansion in all variables or just a partial expansion in the variable of your choice.
I haven't explored the full functionality of this calculator and I'm sure that in many other aspects it outperforms TI-89 but Hp 50g is starting to strike me as limited. I'm hoping someone can prove me wrong either by describing a way around the problem I pointed out or by explaining in what respects it is superior to TI-89.