Re: how to find polynomial roots in OCTAVE?help...

[James Sherman Jr.]

Two things I can think of:
1) If your function has only rational exponents, such as:

x^4/3 - 21.3x^1/3 - 4.53^4/3 =0, (I'm assuming you meant x here instead of h in the second argument),  you could solve the related polynomial,
y^4 - 21.3y - 4.53^4/3 = 0 for y, then just have y^3 = x;

or

2) Download and install the optimization package from the octave website and use the fzero function.

Hope this helps.

James

On 6/14/07, jub <address@hidden> wrote:

i'm trying to find the roots of this equation:

x^4/3 - 21.3h^1/3 - 4.53^4/3 =0

in OCTAVE. the problem is the exponent is a fraction. i know how
to find the root if the exponent is in whole number in OCATVE, but how about
exponents? can someone guide me on how to find the root using OCATVE with
exponential functions?

in OCTAVE lets say you want to find the root of:

2x + 4

the syntax will be:

a = [2, 4];
roots(a)

so if you want to find the root of x^(n+1)+ ... + n
( assuming 'n' is an integer >0, and x is the coefficient)
just put:

a = [x, ..., n]; /*so you put the coefficient with the
highest exponent first followed by the
lowest*/
roots(a);


now this is no problem with exponent with type integer...but how about
fractional?




thanks!
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