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Topic: Trouble finding the roots of an equation
Replies: 3   Last Post: Nov 30, 2012 12:24 PM

 Messages: [ Previous | Next ]
 Marcio Barbalho Posts: 15 Registered: 6/2/10
Re: Trouble finding the roots of an equation
Posted: Nov 30, 2012 12:16 PM

"Nasser M. Abbasi" <nma@12000.org> wrote in message <k9aovn\$loc\$1@speranza.aioe.org>...
> On 11/30/2012 10:47 AM, Marcio Barbalho wrote:
> > Dear friends
> > salve salve!
> >
> > I'm trying to find n roots for this equation y = x*tan(x)-10.

>
> around where? here are some roots
>
> EDU>> x=-2*pi:.1:2*pi; %have a quick look first to get an idea
> EDU>> plot(x,x.*tan(x)-10)
> EDU>> sol=fsolve(@(x) x.*tan(x)-10,0.01:1:10);
> EDU>> sol'
>
> ans =
>
> 1.428870011214077
> 1.428870011214077
> 7.228109771675751
> 4.305801413119223
> 4.305801413119223
> 7.228109771627249
> 7.228109771627249
> 7.228109771627249
> 10.200262588295905
> 10.200262588295905
>

> >
> > It seems I'll have to include symbolic calculation, which I
> >was trying to avoid in order to speed up the processing!
> > So I wonder how I could transform y into a series and get n of its infinite roots.
> >
> > Any help will be very much appreciated!
> >

>
> --Nasser

Thank you very much, if you lived here I would buy you a beer. :)

Date Subject Author
11/30/12 Marcio Barbalho
11/30/12 Nasser Abbasi
11/30/12 Marcio Barbalho
11/30/12 Roger Stafford