Cubic polynomial - complex coefficients HELP ME PLEASE

Hello people!

Help would be greatly appreciated... z^{3} + (1 - 4i)z^{2} + (17 - 16i)z + (-87 - 116i) = 0, where z = 3 + 4i is one of the roots...

step by step working would be fandabadosy too; I know it's pretty basic but I've gone COMPLETELY blank

Cheers!

Re: Cubic polynomial - complex coefficients HELP ME PLEASE

You just apply Ruffini with the root you have. You end up with

Re: Cubic polynomial - complex coefficients HELP ME PLEASE

Quote:

Originally Posted by

**dynamic** Hello people!

Help would be greatly appreciated... z^{3} + (1 - 4i)z^{2} + (17 - 16i)z + (-87 - 116i) = 0, where z = 3 + 4i is one of the roots...

step by step working would be fandabadosy too; I know it's pretty basic but I've gone COMPLETELY blank

This is not a homework service

You can find the exact answer on the web.

To do it for yourself, divide the polynomial by to reduce it to a quadratic that you can solve.