Question about Casio fx-115MS

[Jack Crane]

Robert Monsen <rcsurname@comcast.net> wrote in news:ecOpd.672275$8_
6.309637@attbi_s04:

Steve Evans wrote:
On Thu, 25 Nov 2004 23:46:53 GMT, Steve Evans
smevans@jif-lemon.co.mars> wrote:


On Thu, 25 Nov 2004 03:24:09 -0800, Jack Crane <jdcrane7@yahoo.com
wrote:


Steve Evans <smevans@jif-lemon.co.mars> wrote in
news:f2fbq0hhscpcro1rvcvdacidvhtq5l0t4h@4ax.com:


On Thu, 25 Nov 2004 02:20:48 -0800, Jack Crane <jdcrane7@yahoo.com
wrote:


What does the Rnd key (SHIFT 0) (in the lower-left corner) on the
Casio fx- 115MS calculator do, and how is it used?

It rounds off the internal value contained in the Y-register so it
equals the displayed value.

Could you give me an example that includes the keys to push?

I guessso, but its rather late now where I am. I'll do it ifircall
tomorrow


Well here I amagain. Your calculator has three main registers for
holding current values, X, Y, and K registers. they each have three
particular jobs to do. X is the working reg., holding the displayed
value, Y's like a variable reserve reg. for any ohter 'reserve' value
and K holds fixed, programmable values. If you divide 50 by 10 then
press <shift><x-y> you'll get the result 0.2 ratger tgan 5. Fool
around with these registers and the RND function and yo';ll see what
goes down. BTW, if you don't know what it does, why do you need to use
it?
Have fun.




Try this sequence:

PI = sin ans

you get zero.

OK, in RAD MODE I pushed SHIFT-PI, =, sin, ANS, and got 0. That's fine.

Now, try

PI rnd = sin ans

you get 3.59n (or 3.59e-9)

I pushed SHIFT-PI, SHIFT-Rnd, =, sin, ANS, and got 0 again, not your
3.59n. Do you have the fx-115MS?

The rnd rounded PI to the digits on the display, so the answer wasn't
exact wrt the internal registers.

I can't think of a good use for this key. You almost never care about
more than a few significant digits anyway.

Thanks for trying to help.

Jack

 

[Robert Monsen]

Jack Crane wrote:

Robert Monsen <rcsurname@comcast.net> wrote in news:ecOpd.672275$8_
Try this sequence:

PI = sin ans

you get zero.


OK, in RAD MODE I pushed SHIFT-PI, =, sin, ANS, and got 0. That's fine.

Now, try

PI rnd = sin ans

you get 3.59n (or 3.59e-9)


I pushed SHIFT-PI, SHIFT-Rnd, =, sin, ANS, and got 0 again, not your
3.59n. Do you have the fx-115MS?


The rnd rounded PI to the digits on the display, so the answer wasn't
exact wrt the internal registers.

I can't think of a good use for this key. You almost never care about
more than a few significant digits anyway.


Thanks for trying to help.

Jack

Sorry, I got the directions wrong, you need to put the value PI into the
internal registers before you hit shift rnd. So, try this:

shift PI = (puts it into the register)
shift rnd (rounds register to whats on the display,
subtracting some delta)
sin ans = (computes sin(PI - delta))

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Jack Crane]

Robert Monsen <rcsurname@comcast.net> wrote in news:JLQpd.149903$HA.65909
@attbi_s01:

Jack Crane wrote:
Robert Monsen <rcsurname@comcast.net> wrote in news:ecOpd.672275$8_
Try this sequence:

PI = sin ans

you get zero.


OK, in RAD MODE I pushed SHIFT-PI, =, sin, ANS, and got 0. That's fine.

Now, try

PI rnd = sin ans

you get 3.59n (or 3.59e-9)


I pushed SHIFT-PI, SHIFT-Rnd, =, sin, ANS, and got 0 again, not your
3.59n. Do you have the fx-115MS?


The rnd rounded PI to the digits on the display, so the answer wasn't
exact wrt the internal registers.

I can't think of a good use for this key. You almost never care about
more than a few significant digits anyway.


Thanks for trying to help.

Jack


Sorry, I got the directions wrong, you need to put the value PI into the
internal registers before you hit shift rnd. So, try this:

shift PI = (puts it into the register)
shift rnd (rounds register to whats on the display,
subtracting some delta)
sin ans = (computes sin(PI - delta))

Ok, got it. Thanks.

BTW how did you learn this? I've found online PDFs of both sheets that came
with my calculator, and that constitute its manual. They are at
<ftp.casio.co.jp/pub/world_manual/ edu/en/fx100MS_115MS_E.pdf>

And

<http://ftp.casio.co.jp/pub/world_manual/edu/en/fx115MS_991MS_E.pdf>

And Rnd is mentioned in neither of them.

I'm now trying to figure out CALC. Could you take a look at the PDF of the
second link I've quoted (or at your calculator's manual)? The CALC Memory
section is on page 6 of the PDF. The example there doesn't work correctly
for me. When I finish entering the function the screen shows "x-cubed + 3x
- 12", which looks good. Then I push CALC and answer "7" for the "x?"
prompt. I get 352 (instead of the correct 58). And for x=8 I get 524 (not
76). Any ideas?

Thanks,

Jack

 

[Robert Monsen]

Jack Crane wrote:

Robert Monsen <rcsurname@comcast.net> wrote in news:JLQpd.149903$HA.65909
@attbi_s01:


Jack Crane wrote:

Robert Monsen <rcsurname@comcast.net> wrote in news:ecOpd.672275$8_

Try this sequence:

PI = sin ans

you get zero.


OK, in RAD MODE I pushed SHIFT-PI, =, sin, ANS, and got 0. That's fine.


Now, try

PI rnd = sin ans

you get 3.59n (or 3.59e-9)


I pushed SHIFT-PI, SHIFT-Rnd, =, sin, ANS, and got 0 again, not your
3.59n. Do you have the fx-115MS?



The rnd rounded PI to the digits on the display, so the answer wasn't
exact wrt the internal registers.

I can't think of a good use for this key. You almost never care about
more than a few significant digits anyway.


Thanks for trying to help.

Jack


Sorry, I got the directions wrong, you need to put the value PI into the
internal registers before you hit shift rnd. So, try this:

shift PI = (puts it into the register)
shift rnd (rounds register to whats on the display,
subtracting some delta)
sin ans = (computes sin(PI - delta))



Ok, got it. Thanks.

BTW how did you learn this? I've found online PDFs of both sheets that came
with my calculator, and that constitute its manual. They are at
ftp.casio.co.jp/pub/world_manual/ edu/en/fx100MS_115MS_E.pdf

And

http://ftp.casio.co.jp/pub/world_manual/edu/en/fx115MS_991MS_E.pdf

And Rnd is mentioned in neither of them.

I'm now trying to figure out CALC. Could you take a look at the PDF of the
second link I've quoted (or at your calculator's manual)? The CALC Memory
section is on page 6 of the PDF. The example there doesn't work correctly
for me. When I finish entering the function the screen shows "x-cubed + 3x
- 12", which looks good. Then I push CALC and answer "7" for the "x?"
prompt. I get 352 (instead of the correct 58). And for x=8 I get 524 (not
76). Any ideas?

Thanks,

Jack

The answer is, actually 352:

7^3 = 343
3x7 = 21

so

343 + 21 - 12 = 352

Sounds like you are doing it right...

Now, try to figure out 'solve'.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Jack Crane]

Robert Monsen <rcsurname@comcast.net> wrote in
news:G94qd.161976$R05.64212@attbi_s53:

Jack Crane wrote:
Robert Monsen <rcsurname@comcast.net> wrote in
news:JLQpd.149903$HA.65909 @attbi_s01:


Jack Crane wrote:

Robert Monsen <rcsurname@comcast.net> wrote in news:ecOpd.672275$8_

Try this sequence:

PI = sin ans

you get zero.


OK, in RAD MODE I pushed SHIFT-PI, =, sin, ANS, and got 0. That's
fine.


Now, try

PI rnd = sin ans

you get 3.59n (or 3.59e-9)


I pushed SHIFT-PI, SHIFT-Rnd, =, sin, ANS, and got 0 again, not your
3.59n. Do you have the fx-115MS?



The rnd rounded PI to the digits on the display, so the answer
wasn't exact wrt the internal registers.

I can't think of a good use for this key. You almost never care
about more than a few significant digits anyway.


Thanks for trying to help.

Jack


Sorry, I got the directions wrong, you need to put the value PI into
the internal registers before you hit shift rnd. So, try this:

shift PI = (puts it into the register)
shift rnd (rounds register to whats on the display,
subtracting some delta)
sin ans = (computes sin(PI - delta))



Ok, got it. Thanks.

BTW how did you learn this? I've found online PDFs of both sheets
that came with my calculator, and that constitute its manual. They
are at <ftp.casio.co.jp/pub/world_manual/ edu/en/fx100MS_115MS_E.pdf

And

http://ftp.casio.co.jp/pub/world_manual/edu/en/fx115MS_991MS_E.pdf

And Rnd is mentioned in neither of them.

I'm now trying to figure out CALC. Could you take a look at the PDF
of the second link I've quoted (or at your calculator's manual)? The
CALC Memory section is on page 6 of the PDF. The example there
doesn't work correctly for me. When I finish entering the function
the screen shows "x-cubed + 3x - 12", which looks good. Then I push
CALC and answer "7" for the "x?" prompt. I get 352 (instead of the
correct 58). And for x=8 I get 524 (not 76). Any ideas?

Thanks,

Jack

The answer is, actually 352:

7^3 = 343
3x7 = 21

so

343 + 21 - 12 = 352

Sounds like you are doing it right...

Oops. Thanks for checking this. In dim light with dimming eyes, from the
manual I had read X-cubed instead of X-squared.

Now, try to figure out 'solve'.

OK! I'll try later today.

Jack

 

[Robert Monsen]

Jack Crane wrote:

Robert Monsen <rcsurname@comcast.net> wrote in news:G94qd.161976$R05.64212
@attbi_s53:


Now, try to figure out 'solve'.



OK, Robert, you got me. Twice I've entered thru SHIFT SOLVE and the first
prompt is "B?"; and I'm not given a chance to enter A. Does this really
work?

Tried a simpler equation, A-squared = B X C-squared, with A=8, C=2. Same
thing happened.

Jack

Solve uses an iterative solver to try to figure out a numerical
solution. Say you want to figure out the right resistor value to make
divider, but you were too lazy to do the algebra in your head. If your
input voltage was 10 volts, and you wanted 1.7 volts out, you could type

1.7 alpha = 10 * alpha A / ( alpha A + alpha B) shift solve

You then get a prompt for A, as in "A? ". Say you want to solve for A.
Then, hit the down key (the bottom of the circular key). You get a "B?"
prompt. Enter a value for B. (say you have a 10k resistor)

10000 =

then get back to the A? prompt by typing up arrow (the top of the
circular key) and type

shift solve

it'll crank for a bit, then display A= on the first line, and 2.048...k
on the second line. Thus, for a value of B=10k, a value of A=2.05k will
get you 1.7V.

The trick is to use the up and down key to enter values for variables
you have values for, and then use shift solve on the one you want the
value for.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Robert Monsen]

Jack Crane wrote:

Robert Monsen <rcsurname@comcast.net> wrote in
news:UDwqd.411559$wV.308600@attbi_s54:


Solve uses an iterative solver to try to figure out a numerical
solution. Say you want to figure out the right resistor value to make
divider, but you were too lazy to do the algebra in your head. If your
input voltage was 10 volts, and you wanted 1.7 volts out, you could
type

1.7 alpha = 10 * alpha A / ( alpha A + alpha B) shift solve

You then get a prompt for A, as in "A? ". Say you want to solve for A.
Then, hit the down key (the bottom of the circular key). You get a
"B?" prompt. Enter a value for B. (say you have a 10k resistor)

10000 =

then get back to the A? prompt by typing up arrow (the top of the
circular key) and type

shift solve

it'll crank for a bit, then display A= on the first line, and
2.048...k on the second line.


Did this twice and both times with A= on the first line, the second line
was 0.

Thus, for a value of B=10k, a value of A=2.05k will

get you 1.7V.

The trick is to use the up and down key to enter values for variables
you have values for, and then use shift solve on the one you want the
value for.


Tried a really simple equation, 3 = A*B (3 Alpha = Alpha A * Alpha B),
with B=3. Again, with A= showing on first line, second line showed 0.

Jack

Again, you switch to B using the 'down' key, which is the bottom of the
circular key. Enter the values for the unknowns you want, and then
select the one you want to solve for. enter 'shift solve' and it will
solve the equation if it can do it using iteration.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Jack Crane]

Robert Monsen <rcsurname@comcast.net> wrote in news:e7Pqd.175760
$R05.45470@attbi_s53:

Tried a really simple equation, 3 = A*B (3 Alpha = Alpha A * Alpha B),
with B=3. Again, with A= showing on first line, second line showed 0.

Jack

Again, you switch to B using the 'down' key, which is the bottom of the
circular key. Enter the values for the unknowns you want, and then
select the one you want to solve for. enter 'shift solve' and it will
solve the equation if it can do it using iteration.

Am I wrong to expect the calculator to solve "3=A*B" for A, given B = 3?
I believe I did exactly what you said to do. I'll spell out completely
the keys I pushed : 3, ALPHA, =, ALPHA, A, *, ALPHA, B, SHIFT, SOLVE,
down-arrow, 3, =, up-arrow, SHIFT, SOLVE. At this point the top line
shows A=; the bottom line shows 0. (by * I mean the multiplication key,
"X").

Thanks for being so patient with me.

Jack

 

[Robert Monsen]

Jack Crane wrote:

Robert Monsen <rcsurname@comcast.net> wrote in news:e7Pqd.175760
$R05.45470@attbi_s53:


Tried a really simple equation, 3 = A*B (3 Alpha = Alpha A * Alpha B),
with B=3. Again, with A= showing on first line, second line showed 0.

Jack

Again, you switch to B using the 'down' key, which is the bottom of the
circular key. Enter the values for the unknowns you want, and then
select the one you want to solve for. enter 'shift solve' and it will
solve the equation if it can do it using iteration.



Am I wrong to expect the calculator to solve "3=A*B" for A, given B = 3?

No, it works for me.

I believe I did exactly what you said to do. I'll spell out completely
the keys I pushed : 3, ALPHA, =, ALPHA, A, *, ALPHA, B, SHIFT, SOLVE,
down-arrow, 3, =, up-arrow, SHIFT, SOLVE. At this point the top line
shows A=; the bottom line shows 0. (by * I mean the multiplication key,
"X").

Thanks for being so patient with me.

Jack

Make sure you are in 'comp' mode, not 'cmplx' mode. The solve function
does not work in complex mode. Enter 'mode clr' and then '1' to enter
'comp' mode.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Robert Monsen]

Jack Crane wrote:

Robert Monsen <rcsurname@comcast.net> wrote in news:3GWqd.169549$HA.22176
@attbi_s01:


After entering your formula for 3=A*B, can you switch between "A=" and
"B=" on the top display line using up and down arrow?



No. After "A=" appears, up-arrow produces "3", and I'm stuck there.
Down-arrow doesn't work after "A=" appears.

Jack

Look at the calculator. There is a big round button right underneath the
center of the display. The up and down buttons are on the top and bottom
of that. Is that what you are pushing? If not, then that's your problem.
If so, then your calculator is broken.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Jack Crane]

Robert Monsen <rcsurname@comcast.net> wrote in
news:Jfcrd.695662$8_6.282472@attbi_s04:

Jack Crane wrote:
Robert Monsen <rcsurname@comcast.net> wrote in
news:3GWqd.169549$HA.22176 @attbi_s01:


After entering your formula for 3=A*B, can you switch between "A="
and "B=" on the top display line using up and down arrow?



No. After "A=" appears, up-arrow produces "3", and I'm stuck there.
Down-arrow doesn't work after "A=" appears.

Jack

Look at the calculator. There is a big round button right underneath
the center of the display. The up and down buttons are on the top and
bottom of that. Is that what you are pushing? If not, then that's your
problem. If so, then your calculator is broken.

Yes, that's what I'm pushing.

Thanks,

Jack