CASIO CLASSWIZ fx-991EX

[lrdheat]

Just got the CLASSWIZ. Happy to say that solve application allows integrals and d/dx to be used, allowing easy calculations of extremums.

Nice little calculator, display scree, nice shirt pocket size.

All clears, turning calculator off clears history as will a battery change. Has solar panel to compliment an LR44 button battery.

Haven't checked much more out.

Does cross and dot products of 3D vectors, does 4 by 4 matrix calculations.

As proficient as CASIO 9860gii in returning answers in fractions, pi, square roots.

[Thomas Radtke]

(07-28-2015 02:25 AM)lrdheat Wrote:  Just got the CLASSWIZ. Happy to say that solve application allows integrals and d/dx to be used, allowing easy calculations of extremums.

Interesting to note that this is (according to the german manual) not the case for the 991 DE X, which jebem assumed to be equal. Either this is a different machine or there's an error in the manual.

Anyway, being a former Casio user I'm happy it's not behind its competitor TI36x pro in this respect.

[Tugdual]

I'm more and more attracted by a Casio considering the recurrent disappointing quality of hp products made in China. Do you know where this product was made? How are casing and keyboard? Is the screen as clear bright and contrasted as on pictures? How is the font? Small characters or easy to read the day I forget my glasses ;-)

[Dave Britten]

(07-28-2015 05:46 AM)Tugdual Wrote:  I'm more and more attracted by a Casio considering the recurrent disappointing quality of hp products made in China. Do you know where this product was made? How are casing and keyboard? Is the screen as clear bright and contrasted as on pictures? How is the font? Small characters or easy to read the day I forget my glasses ;-)

My general opinion of Casios is that they have excellent features and speed, but the weak integration of features makes it cumbersome and/or impossible to reuse data or results between different functions. If you're using a Casio, get used to switching between function-specific modes an awful lot. But the fx-9860g is very user friendly, fast, and packs a lot of features, as long as you don't mind sacrificing the more advanced programming, reuse of data, and integration* you'd expect from, say, an HP 48.


*of features, not calculus

[lrdheat]

The display is not e-book like...not as sharp contrast-wise as the pictures, but much less "blocky" looking numbers/letters.

The 9860gii is more friendly for using an equation/function through a variety of applications in the calculator. I can't see a way to store an equation or an f(x) to use/manipulate from one calculating environment to the next (table to solve or main calculating area to solve, etc.) on the CLASSWIZ. TI 36X Pro also more friendly in this respect.

I can use textbook entry for solve which is nice, and a longer equation can be entered than in the TI 36X Pro.

The keyboard labels are a bit small and in poor light, I had some difficulty with seeing the alpha letter labels. The base choice labels look to be hard to see in low light.

Haven't messed with spread sheet.

That said, not unhappy with it...

[Marcio]

Calculators of today are made strictly for education. The new 991 Ex features high resolution display and many other improvements but lacks basic functions like hyperbolic.

I was (am) looking for a replacement for the 35s but haven't find anything that comes close.

[lrdheat]

It does hyperbolic trigonometric calculations...

[lrdheat]

In the solve environment, if one does a d/dx=0 calculation of some equation to find an extremum, one can edit back through the equation, deleting the d/dx which just leaves the equation. "x" that solved d/dx will still be in "x". If you press "=", you will get f(x) at the "x" that represents the extremum.

The integration is not as quick as on the 9860gii.

Still, a nice shirt pocket calculator.

[lrdheat]

If one wanted to find another extremum, I just discovered that by going back to what is now f(x), it can easily be made back into d/dx of f(x) by taking the curser to the front of the equation and, using insert, put in d/dx. then go to end and make it where "x=x" =0, and press solve, enter in your next guess for an "x".

Without inserting d/dx at the beginning using insert, one has to re-enter the whole thing all over again to find new points of interest.

Neat!

[lrdheat]

While I'm at it, I do want to say that it is nice to be able to use textbook entry in the calculation, solve, and table modes.

[jebem]

(07-30-2015 03:27 AM)lrdheat Wrote:  While I'm at it, I do want to say that it is nice to be able to use textbook entry in the calculation, solve, and table modes.

Hi,

I'm curious to know about what would be the firmware revision of your International (English) version of the Classwiz.
If you like and have the time, you can find instructions here on how to get this information.

Thank you!

[Marcio]

(07-29-2015 03:01 AM)lrdheat Wrote:  It does hyperbolic trigonometric calculations...

Forgive my ignorance but could you show how? I suppose it should be right on the keyboard?

Thanks

Marcio

[fhub]

(07-30-2015 06:58 PM)Marcio Wrote:  Forgive my ignorance but could you show how? I suppose it should be right on the keyboard?

No, the 6 HYP functions are in a menu, you get it with [OPTN][1]

Franz

[lrdheat]

Much longer equations can be entered in textbook mode than the TI 36X Pro! I just entered integral of 1/tan(2x)sin(2x) from pi/6 to pi/4 -10^-12 + integral 1/tan(2x)sin(2x) from pi/4 +10^-12 to pi/3 which srolled way off initial display screen, and it quickly came up with the decimal approximation which I verified accurate to all digits displayed. If I integrated from pi/6 to pi/4, it balks due to undefined point at pi/4. By the way, Prime does fine with pi/6 to pi/3 in home, but hangs with this problem in CAS.

[Gerald H]

(08-01-2015 03:56 PM)lrdheat Wrote:  Much longer equations can be entered in textbook mode than the TI 36X Pro! I just entered integral of 1/tan(2x)sin(2x) from pi/6 to pi/4 -10^-12 + integral 1/tan(2x)sin(2x) from pi/4 +10^-12 to pi/3 which srolled way off initial display screen, and it quickly came up with the decimal approximation which I verified accurate to all digits displayed. If I integrated from pi/6 to pi/4, it balks due to undefined point at pi/4. By the way, Prime does fine with pi/6 to pi/3 in home, but hangs with this problem in CAS.

Yes, yes, all very well praising a cheap Casio but where's the colour capable display?

Prioritize: What's more important, getting the answer right & not re-booting or a colour display?

[Marcio]

If it is not too much to ask, please, evaluate the following with the 991EX to full 12-dig precision:

\[ARG(e^{\frac{\pi*i}{180\times1E7}}) \]

Not all calculators (including HPs) can get all digits correct: 9.999... E-8. In actuality, I have never seen any Casio do badly on tests like this, cheap calculators and many android emulators, OTOH, will fail horribly.

Thanks.

Marcio

[Gerald H]

In degree mode HP 48S returns 9.99999999998E-8

[Marcio]

(08-01-2015 07:34 PM)Gerald H Wrote:  In degree mode HP 48S returns 9.99999999998E-8

Acceptable. The correct answer is 1E-7 though. The 35s will return 9.99994698998E-8.

[lrdheat]

Complex capabilities on the fx-991EX is quite limited. Pretty much limited to +,-,/,*,^integer powers. Trig operation not supported. The 9860, while not complete in it's complex capability, can do much more. It can take sin 1.57+1.52i, but then can't return asin of that result.

That said, it's fun to check out what the $20 level calculators can do! They are calculators, after all, not sophisticated high level devices! The 991EX is a new nice shirt pocketable calculator. The 9860 is a much more capable barely shirt pocketable device at $80ish. NOTHING holds a candle to WP 34 as a pocketable device except perhaps for easily solving equations for multiple variables and easy 3D vector operations...

[lrdheat]

I would be quite remiss if I didn't include the Prime as a most capable shirt pocketable device...I was centering my post on low cost, non CAS devices!