Sharp EL-W516X Calculation Examples Manual

[Matt Agajanian]

Hello all.

Happy to announce that my new baby arrived today!! And with it came an exhuberant joy at how glorious it looks and how impressed I am with its design. It looks and feels as if it were designed with a professional appearance much like our HPs did in the days of Classic lineage.

Even though I have been able to locate a PDF of the Operations Manual, the Calculation Examples manual eludes my search.

I would appreciate it if someone could direct me as to where I can download the PDF of that Calculation Examples supplement.

Thanks in advance.

[Steve Simpkin]

Matt,

If you find it let us know too.

There is a good comparison between the SHARP EL-W516 and the CASIO fx-115ES calculators at:
http://members.bex.net/jtcullen515/Math8.htm

More than a simple comparison, the two volumes presented here (175 pages) are also a good tutorial on how to use these models with a lot of examples. The information is usable for newer Casio and Sharp scientific calculator models as well.

I picked up a Sharp EL-W535X a couple of months ago at a local Kmart. It is the little brother of your model. It was on sale for less than $10 and all alone on its peg. Its not like I "needed" another calculator but couldn't pass up a Text Book display calculator for that price.

It's not important. It's a minor compulsion. I can deal with it if I want to.
http://m.youtube.com/watch?v=vWz0AWtwdoA

[Steve Simpkin]

Sharp has a number of documents for educational support at:
http://sharp-world.com/contents/calculator/support/

In particular the Classroom Materials for WriteView calculators at:
http://sharp-world.com/contents/calculat...index.html

and the GuideBook document for the EL-W531 at:
http://sharp-world.com/contents/calculat...ELW531.pdf

Might apply somewhat towards your model.

[Steve Simpkin]

There is also a Teacher's Guide available for the EL-W516B which is almost identical to your model at:
http://files.sharpusa.com/Downloads/ForH...sGuide.pdf

[lrdheat]

Just discovered an interesting item that the TI 36pro can do that the CASIO fx-115ES PLUS cannot do...the Casio cannot include a d/dx in a solve problem. The TI can! Enter solve, enter the d/dx, set where x equal to x, enter a guess for x, solve for x, and you get an answer for x when d/dx=0 which will be a min or max of f(x). The variable x now has the number that solve arrived at. If you type in the equation and enter it, you get the value of f(x) at that point. Nicely, since x root of y is available, answers are available for negative numbers where something like 3 root of x is involved.

[CR Haeger]

(04-11-2014 02:50 PM)lrdheat Wrote:  Just discovered an interesting item that the TI 36pro can do that the CASIO fx-115ES PLUS cannot do...the Casio cannot include a d/dx in a solve problem. The TI can! Enter solve, enter the d/dx, set where x equal to x, enter a guess for x, solve for x, and you get an answer for x when d/dx=0 which will be a min or max of f(x). The variable x now has the number that solve arrived at. If you type in the equation and enter it, you get the value of f(x) at that point. Nicely, since x root of y is available, answers are available for negative numbers where something like 3 root of x is involved.

lrdheat - thanks for the cool tip! I tried this earlier and it stayed busy for a while so I didnt think it would work...

I found these other related (undocumented) operations the TI36X can do:
- Use 2nd Integral in num-solve to solve for uppper, lower limits or even coefficients used in the expression.
- Both 2nd d/dx and Integral can be used in data/formulas and table/edit function --> gives numerical f(x), f'(x) and integral f(x) in the table(s)

[Matt Agajanian]

(04-11-2014 02:50 PM)lrdheat Wrote:  Just discovered an interesting item that the TI 36pro can do that the CASIO fx-115ES PLUS cannot do...the Casio cannot include a d/dx in a solve problem. The TI can! Enter solve, enter the d/dx, set where x equal to x, enter a guess for x, solve for x, and you get an answer for x when d/dx=0 which will be a min or max of f(x). The variable x now has the number that solve arrived at. If you type in the equation and enter it, you get the value of f(x) at that point. Nicely, since x root of y is available, answers are available for negative numbers where something like 3 root of x is involved.

Funny you should bring that up. In my translation from HP to my 36X Pro, I tried that same method to see if, unlike the 34C, 42S and onward, Solve and Integrate could perhaps be nested. As the 36X Pro's technology is 20+ years later, I thought to test if the 36X Pro would be constrained to the same nesting usage limitation. So, I decided to test that using the most direct approach of finding a local min/max, find a zero of the function's derivative. Lo and behold, when I used the 36X Pro's Solver for an equation of the form d/dx(func|x=some value), it worked!!

Great minds think alike!

**Additional note:

Using this same idea with an example, d(3x^2+5x)/dx|x=10 as the equation and activating the Solver on the Sharp EL-W516X yields a syntax error.

[lrdheat]

Don't have the Sharp. On the TI, the solver template presents one with 0=function to be solved. Instead of entering a number for |x=?, I make it x=x, and the TI finds the solution for the differential. What happens on the Sharp if you do |x=x?

[Matt Agajanian]

Either way, with x=0 or x=x, after I choose Solver from the EL-W516X Math menu, 'Syntax Error 01' is the next thing that pops up.

[lrdheat]

Amazed...discovered another neat thing on the TI 36pro! I can define a function in table (option 2, then hit f(1 and go to numerical solver, hit d/dx, hit enter placing f( into the equation, make it into f(x), take the differential as x=x, and get a min or max point. Without having to re type my equation, I can now go to the home screen, hit enter, and f(x) will come up, evaluated for the x that was calculated for f'(x).

Really quite a calculator for $20.

[Matt Agajanian]

(04-12-2014 05:17 PM)lrdheat Wrote:  Amazed...discovered another neat thing on the TI 36pro! I can define a function in table (option 2, then hit f(1 and go to numerical solver, hit d/dx, hit enter placing f( into the equation, make it into f(x), take the differential as x=x, and get a min or max point. Without having to re type my equation, I can now go to the home screen, hit enter, and f(x) will come up, evaluated for the x that was calculated for f'(x).

Really quite a calculator for $20.

Your description is quite fascinating. So I can do this correctly, could you please describe the steps a little more, perhaps a step-by-step example of this?

Thanks

[lrdheat]

Press table, select choice 2, create your function, clear, press table, choose choice 1 and make f( f(x). Go to num-solv and get 0= and go to right side of = and put d/dx in, hit enter which will place f(x) in the differential, make x=x! hit enter to enter solve template. Choose a guess and solve for x. You can then quit, press table, select 1 and enter getting f( make that f(x), enter and get f(x) value. Press x, enter, and get the value of x.

[CR Haeger]

(04-12-2014 06:24 PM)lrdheat Wrote:  Press table, select choice 2, create your function, clear, press table, choose choice 1 and make f( f(x). Go to num-solv and get 0= and go to right side of = and put d/dx in, hit enter which will place f(x) in the differential, make x=x! hit enter to enter solve template. Choose a guess and solve for x. You can then quit, press table, select 1 and enter getting f( make that f(x), enter and get f(x) value. Press x, enter, and get the value of x.

Thanks. I'll try this.

I think you can solve for f'(x)=0 directly in num solve:
Y = d/dx (your expression containing x)|x=x
Solve for x

Let me know if it works - maybe you already posted this earlier? Yes I think the TI36 may be as useful or more so than the $100+ graphing calcs.

[lrdheat]

Yes, the num-solv can find d/dx=0 directly. The rest of my operations allowed for me to find f(x) at that value without having to re type the function. What is convenient at this point is that if you are going to find d/dx for multiple critical values for one function, f(x) is still defined, and you can directly get and display x and f(x) in the home screen if desired.

[Matt Agajanian]

Thanks!

Tried it and it worked.

Although, both the Casio 115ES Plus and Sharp EL-W516X had a fit when I tried. Perhaps there's a different method to their madness.

[supernumero]

(03-04-2014 01:49 AM)Matt Agajanian Wrote:  Happy to announce that my new baby arrived today!! And with it came an exhuberant joy at how glorious it looks and how impressed I am with its design. It looks and feels as if it were designed with a professional appearance much like our HPs did in the days of Classic lineage.

I got an EL-W516X a few months ago. Unfortunately, I found what I deem an unacceptably low precision computing a natural log:

Correct value to 9 significant figures:
ln(0.9999995) = -5.00000125E-7

EL-W516X:
ln(0.9999995) = -5.00000075E-7

Absolute error: 5E-14
Relative error: 1E-7

So, only 7 significant figures of the answer given by the calculator are correct---a loss of 3 significant figures!

(I cannot remember the source for this test. IIRC, some vintage scientific calculators gave the wrong answer -5E-7, which is correct to only 6 significant figures. The current results are only marginally better.)

I also have a Sharp EL-506X, which gives the same wrong answer, but none of several other calculators (from different manufacturers) that I tested gave a wrong answer.

I liked the EL-W516X quite fine until I decided I didn't trust it in view of the above...

S.Numero

[lrdheat]

Talking of accuracy, 36pro "manual" says d/dx calculated with epsilon=1E-3 when using MathPrint mode. User can define epsilon if desired in classic mode. For equation entry, slightly more than 40 characters are available in MathPrint mode. I believe a good deal more is possible in classic mode, but don't know more specifically.

[CR Haeger]

(04-12-2014 06:24 PM)lrdheat Wrote:  Press table, select choice 2, create your function, clear, press table, choose choice 1 and make f( f(x). Go to num-solv and get 0= and go to right side of = and put d/dx in, hit enter which will place f(x) in the differential, make x=x! hit enter to enter solve template. Choose a guess and solve for x. You can then quit, press table, select 1 and enter getting f( make that f(x), enter and get f(x) value. Press x, enter, and get the value of x.

Sorry to bother but I'm running into syntax errors trying to replicate this.
- How do you make f( f(x)?
- how do you paste f(x) into the differential?

Can you do this step by step with a simple expression?

[lrdheat]

A simple example...press table, select choice 2, press clear, and type in the function, shay, sin(x). Hit enter. This takes you to the table setup. You can directly go to num-solve from this screen by pressing 2nd num-solv. Here, you can make 0=d/dx. With curser inside of (), press table, enter choice 1. This brings you back to the num-solv screen. Type an x inside (), make|x=x. This takes you to solve. Try x=1, go down to solve and highlight x and enter. It will come up with ~1.57 if in radians. Quit. This puts you in home screen. Type x and enter, getting ~1.57. Press table, enter choice 1. This brings back the home screen. Type x so that you have f(x) and enter, and you will get f(x)=1 which is f(~1.57).

Of course, making a table can be neat also, and can help with choosing a guess to enter into the solver.

I did find an example that the 36pro balks at in num-solve for finding d/dx=0. This came from hp 15 guide book page 184. The pro36 comes up with domain error when solving d/dx=0 for 5000*(1-e^(-x/20))-200*x. It does make a table without difficulty. Not sure why this happens. The pro36 wasn't bothered with d/dx= for odd number roots where x<0 that I tried...seems like the pro36 solves a good many d/dx=0 functions.

Good luck!

[lrdheat]

Just a side note...the WP 34s solves all the f'(x)=0 problems that failed on my other calculators!
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