[R] Is there a way to find all roots of a polynomial equation in R?

Rolf Turner rolf.turner at xtra.co.nz
Wed Apr 18 22:49:48 CEST 2012


On 19/04/12 08:14, Michael wrote:
> Is there a way to find all roots of a polynomial equation?
>
> Lets say
>
> x^5+a*x^4+b*x^3+c*x^2+d*x+e=0
>
>
> how to find its all roots?

I believe that Galois (or maybe it was Abel) proved that this
is *NOT* possible, a couple of centuries ago.

However if you are thinking of *numerical* methods (i.e. supplying
numerical values for a, b, ..., e before you start) then polyroot()
will do it for you.  As

     RSiteSearch("zeroes of polynomial")

would have told you.  (Seventh hit.)

     cheers,

         Rolf Turner



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