# Complex Coefficient Polynomial Roots

• Oct 5th 2010, 06:25 AM
SmeagZ
Complex Coefficient Polynomial Roots
Hey

I am looking for an algorithm which can be used to approximate the complex roots of a complex coefficient polynomial. Such as:

(3-4j)x^4 + (1+2j)x + (-4+1)

The polynomial is not of any specific order, and could be quite large.

Any help would be appreciated as i am completely stuck at the moment.

Thanks.
• Oct 6th 2010, 12:14 AM
CaptainBlack
Quote:

Originally Posted by SmeagZ
Hey

I am looking for an algorithm which can be used to approximate the complex roots of a complex coefficient polynomial. Such as:

(3-4j)x^4 + (1+2j)x + (-4+1)

The polynomial is not of any specific order, and could be quite large.

Any help would be appreciated as i am completely stuck at the moment.

Thanks.

First you need to localise the roots, so that you know where to look. The Cauchy bound and its veriants will do this for you. Newton-Raphson will find complex roots if you start close enough.

CB