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# Complex Numbers watch

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1. I'm doing some extra questions out of a different textbook as revision, so i'm not sure if I should actually be able to do this or not...

So if someone could give me a few hints as to what to do then if I don't recognise it i'll presume I don't need to know how to do this.

Find the roots of the equation giving your answers on the form .

Now I take it they will be complex conjugates, but don't know where to start.
3. Omg. I can't believe I didn't think of that... I think I was expecting it to be harder than it was... Thats my excuse anyway
4. We've all done it, don't worry.
5. What about cubics? Will there always be an easier factor to spot for the third root (ie not a fraction)? So then you can form a quadratic and apply the same method?
6. For the questions they give you, there should be.
7. its either that or they give you one the the complex roots, then you use the fact that if
is a root then is also a root

so the quadratic factor would be
8. Oooo ok cool.
9. you could also find the perfect square(?) so (z+a)^2=b
=)
10. (Original post by Hyeree)
you could also find the perfect square(?) so (z+a)^2=b
=)
Yep - this is called "completing the square" in English.

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Updated: March 8, 2008
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