Roots of a complex number question (1 Viewer)

[ivanradoszyce]

Hi all,

This question comes from Cambridge Chapter 3(C) Q15.

a) Show that every root of the equation is imaginary for

b) Let the roots be represented by the points in the Argand diagram, and let O be the origin.

Show that:



So I have proven a) and found



But I need some direction for part b). I'm assuming I use Vieta's Formula, but don't know exactly how to determine the solution.

 

[scaryshark09]

this is solution to part b

 

[ivanradoszyce]

Thanks.... I was sort of on the right track, but your solution has clarified my confusion. Cheers.