MATLAB: How to find the root of a polynomial

Question

I have this polynomial: P(z) = z.^9 + z.^8 – z.^7 + z.^6 – z.^5 + z + 1

And I'd like to find the roots for it.

How would I go about doing that?

Answer 1

Easiest:

syms z 
P(z) = z.^9 + z.^8 - z.^7 + z.^6 - z.^5 + z + 1; 
rts = vpasolve(P)

Otherwise:

rts = roots([1 1 -1 1 -1 0 0 0 1 1]);

With the same essential result.