MATLAB Central Newsreader - syms x; y=2*x^2=> error???? why to all?

syms x; y=2*x^2=> error???? why to all?

Quynh Tram Nghuyen Thi — Thu, 19 Apr 2012 04:59:16 +0000

hello everyone
as i ve read som books of reference with instructions of detail . its one of them as folwoing:
syms x
y= 2*x^2+5*x;
diff(y)
4*x +5
BUT WHEN I PRACTICED in matlab 7.6 then It CAME ELLOR ryte after the 1st line ( syms x). i really dont undertsand. then HOW I CAN SOLVE MANY EQUATIONS WITH the general variables like above.
its mean that i need to find A DERIVATIVE of 1 FUNCT ION EXPRESSION ( not value ) then ... ANY SOLUTIONS except for the code above??

please give me fast look & feekbacks if poissbile
thanks

Re: syms x; y=2*x^2=> error???? why to all?

Nasser M. Abbasi — Thu, 19 Apr 2012 05:17:07 +0000

On 4/18/2012 11:59 PM, Quynh Tram Nghuyen Thi wrote:
> hello everyone
> as i ve read som books of reference with instructions of detail . its one of them as folwoing:
> syms x
> y= 2*x^2+5*x;
> diff(y)
> 4*x +5
> BUT WHEN I PRACTICED in matlab 7.6 then It CAME ELLOR ryte after the 1st line ( syms x).
>i really dont undertsand. then HOW I CAN SOLVE MANY EQUATIONS WITH the general
>variables like above.
> its mean that i need to find A DERIVATIVE of 1 FUNCT ION EXPRESSION ( not value ) then
>... ANY SOLUTIONS except for the code above??
>
> please give me fast look& feekbacks if poissbile
> thanks

The code works on my Matlab ok 2012a:

----------------
K>> syms x
y= 2*x^2+5*x;
diff(y)
------------------
4*x +5

If you do not get this answer, you should contact Mathworks
technical support. What does the command 'ver' show on
your Matlab?

--Nasser

Re: syms x; y=2*x^2=> error???? why to all?

Quynh Tram Nghuyen Thi — Thu, 19 Apr 2012 06:57:07 +0000

"Nasser M. Abbasi" <nma@12000.org> wrote in message <jmo74j$r1d$1@speranza.aioe.org>...
> On 4/18/2012 11:59 PM, Quynh Tram Nghuyen Thi wrote:
> > hello everyone
> > as i ve read som books of reference with instructions of detail . its one of them as folwoing:
> > syms x
> > y= 2*x^2+5*x;
> > diff(y)
> > 4*x +5
> > BUT WHEN I PRACTICED in matlab 7.6 then It CAME ELLOR ryte after the 1st line ( syms x).
> >i really dont undertsand. then HOW I CAN SOLVE MANY EQUATIONS WITH the general
> >variables like above.
> > its mean that i need to find A DERIVATIVE of 1 FUNCT ION EXPRESSION ( not value ) then
> >... ANY SOLUTIONS except for the code above??
> >
> > please give me fast look& feekbacks if poissbile
> > thanks
>
> The code works on my Matlab ok 2012a:
>
> ----------------
> K>> syms x
> y= 2*x^2+5*x;
> diff(y)
> ------------------
> 4*x +5
>
> If you do not get this answer, you should contact Mathworks
> technical support. What does the command 'ver' show on
> your Matlab?
>
> --Nasser

Thanks Nasser. i just tried as u told already, it came:

MATLAB Version 7.6.0.324 (R2008a)
MATLAB License Number: 161051
Operating System: Microsoft Windows Vista Version 6.1 (Build 7600)
Java VM Version: Java 1.6.0 with Sun Microsystems Inc. Java HotSpot(TM) 64-Bit Server VM mixed mode

then ... it means my ver is old for the code above... i should replace a new ver like your. ryte??
do you another idea again??
iam still waiting for you dear.

Re: syms x; y=2*x^2=> error???? why to all?

Nasser M. Abbasi — Thu, 19 Apr 2012 07:01:05 +0000

On 4/19/2012 1:57 AM, Quynh Tram Nghuyen Thi wrote:

> Thanks Nasser. i just tried as u told already, it came:
>
> MATLAB Version 7.6.0.324 (R2008a)
> MATLAB License Number: 161051
> Operating System: Microsoft Windows Vista Version 6.1 (Build 7600)
> Java VM Version: Java 1.6.0 with Sun Microsystems Inc. Java HotSpot(TM) 64-Bit Server VM mixed mode
>

Can you see the rest of the above command to see if you have the
symbolic toolbox installed?

> then ... it means my ver is old for the code above...

it is not that old. it should work, unless you do not have the
symbolic toolbox. You need to look at the full list of 'ver'
output.

i should replace a new ver like your. ryte??
> do you another idea again??
> iam still waiting for you dear.

--Nasser

Re: syms x; y=2*x^2=> error???? why to all?

Quynh Tram Nghuyen Thi — Thu, 19 Apr 2012 07:33:16 +0000

"Nasser M. Abbasi" <nma@12000.org> wrote in message <jmod7h$707$1@speranza.aioe.org>...
> On 4/19/2012 1:57 AM, Quynh Tram Nghuyen Thi wrote:
>
> > Thanks Nasser. i just tried as u told already, it came:
> >
> > MATLAB Version 7.6.0.324 (R2008a)
> > MATLAB License Number: 161051
> > Operating System: Microsoft Windows Vista Version 6.1 (Build 7600)
> > Java VM Version: Java 1.6.0 with Sun Microsystems Inc. Java HotSpot(TM) 64-Bit Server VM mixed mode
> >
>
> Can you see the rest of the above command to see if you have the
> symbolic toolbox installed?
>
> > then ... it means my ver is old for the code above...
>
> it is not that old. it should work, unless you do not have the
> symbolic toolbox. You need to look at the full list of 'ver'
> output.
>
>
> i should replace a new ver like your. ryte??
> > do you another idea again??
> > iam still waiting for you dear.
>
>
> --Nasser

yea, i give a slow look in its list but it hav no SYMBOLIC word.
it means ... yes, need a installed tooldbox of symbolic??
But how i can install it while i installed the disk 2008 a already.
or i should replace a lastest ver 2012 like yours -( if soo, it abit disappointed, isnt it dear??
m just thinking...
hey, thanks Nasser

Re: syms x; y=2*x^2=> error???? why to all?

Nasser M. Abbasi — Thu, 19 Apr 2012 07:57:29 +0000

On 4/19/2012 2:33 AM, Quynh Tram Nghuyen Thi wrote:

>
> yea, i give a slow look in its list but it hav no SYMBOLIC word.

Then you do not have the symbolic toolbox !

> it means ... yes, need a installed tooldbox of symbolic??

Yes.

> But how i can install it while i installed the disk 2008 a already.

You can buy it as a separate toolbox from your Mathworks store. Go now
and login in there using your account, and you can buy it and download
it electronically and the installer will install it on top of your
current Matlab.

> or i should replace a lastest ver 2012 like yours

That is up to you if you want to upgrade or not before
buying the toolbox. But If you are thinking of upgrading, then better
to do that first, then buy the symbolic toolbox for 2012.

-( if soo, it abit disappointed, isnt it dear??
> m just thinking...
> hey, thanks Nasser

--Nasser

Re: syms x; y=2*x^2=> error???? why to all?

Quynh Tram Nghuyen Thi — Thu, 19 Apr 2012 08:12:13 +0000

"Nasser M. Abbasi" <nma@12000.org> wrote in message <jmogh8$f10$1@speranza.aioe.org>...
> On 4/19/2012 2:33 AM, Quynh Tram Nghuyen Thi wrote:
>
> >
> > yea, i give a slow look in its list but it hav no SYMBOLIC word.
>
> Then you do not have the symbolic toolbox !
>
> > it means ... yes, need a installed tooldbox of symbolic??
>
> Yes.
>
> > But how i can install it while i installed the disk 2008 a already.
>
> You can buy it as a separate toolbox from your Mathworks store. Go now
> and login in there using your account, and you can buy it and download
> it electronically and the installer will install it on top of your
> current Matlab.
>
> > or i should replace a lastest ver 2012 like yours
>
> That is up to you if you want to upgrade or not before
> buying the toolbox. But If you are thinking of upgrading, then better
> to do that first, then buy the symbolic toolbox for 2012.
>
> -( if soo, it abit disappointed, isnt it dear??
> > m just thinking...
> > hey, thanks Nasser
>
> --Nasser

thanks , Nasser.