From: <HIDDEN>
Newsgroups: comp.soft-sys.matlab
Subject: Re: How to solve transecedental equation using matlab
Date: Sat, 14 Feb 2009 20:07:02 +0000 (UTC)
Organization: The MathWorks, Inc.
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Xref: comp.soft-sys.matlab:518278 wrote in message <>...
> Hi friends.....
>     when i was doing a vibration problem i got a equation tanh(ax)+tan
> (ax)=0, which is a transecedental equation....i want the roots of this
> equation..... could any body help me to find out the roots of this
> equation by using matlab

  It should be pointed out that for this particular equation there is no need to resort to matlab for roots.  Ordinary calculus should suffice.  It is clear that there is one root at x = 0.  The derivative of the left side with respect to x is a*(sech(a*x)^2+sec(a*x)^2), which can never be zero assuming a is non-zero.  This means there could never be any other root than at x=0 without violating the famous law of the mean of calculus.

Roger Stafford