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

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Nasser Abbasi

Posts: 6,677
Registered: 2/7/05
Re: how solve this equation with one unknown?
Posted: May 6, 2013 9:14 AM
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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'.


> 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 -


ans =


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