I'm sorry for asking, most likely, idiotic questions, but how would you factor out 2-i? Like Feldoh has done?
Oh my, this math has left my head spinning... Turns out I have no idea about this question at all.
Unfortunately, no, I have no idea. Last algebra class (very smart education system, placing geometry between algebra classes) was about a year and a half ago.
2+i was just given in the question as one of the given roots. I have no idea how to arrive at that answer. Where did the a's go?
Edit...
Homework Statement
Given one root of the equation, find the others.
a3-3a2+a+5=0
Given root: 2-i
The Attempt at a Solution
I know the answers, which are 2+i and -1. And I understand how to get the 2+i since when you square root anything, the answer can be positive or negative, but I have...