Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Software » comp.soft-sys.matlab

Topic: how solve this equation with one unknown?
Replies: 6   Last Post: May 6, 2013 10:38 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Nasser Abbasi

Posts: 5,706
Registered: 2/7/05
Re: how solve this equation with one unknown?
Posted: May 6, 2013 9:14 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

On 5/6/2013 7:59 AM, ghasem wrote:
>
> =======================================
> ok,you right.
> my code (with correction) is as following:
> my code is :
> gr1 = sqrt(-100 - my_var^2);


EDU>> gr1 = sqrt(-100 - my_var^2);
Undefined function or variable 'my_var'.

<SNIP>

>
> I want to solve "det_A" to obtain "my_var" value.
>but I don't know how introduce "my_var" in gr1,gr2 and gr3,such that in "det_A",
>exist "my_var" as a variable.
> if I use from " syms my_var",therefore I can not use from fsolve.
> obviously,in the above,I get this error:
> ??? Undefined function or variable 'my_var'.
> how introduce "my_var" to matlab?
> ghasem
>


-----------------------
syms my_var;
.... your code....
EDU>> det_A

det_A =
- 15000*(- my_var^2 - 70)^(1/2)*(- my_var^2 - 150)^(1/2)*
besselk(1, (- my_var^2 - 70)^(1/2))*
besseli(0, (- my_var^2 - 100)^(1/2))*besseli(0, (- my_var^2 -
....
<snip>


solve(det_A)
------------------------

ans =
9.4713545425002677821820583754265*i

--Nasser





Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.