Find and if:

My idea was to simplify the expression to the normal form (The problem is that i don't know how). And then, by De Moivre's formula I can find the roots.

Any idea on how to simplify the formula and reach the normal form?

Thank you!

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- Aug 12th 2010, 04:50 AMGreenMileComplex number problem!
Find and if:

My idea was to simplify the expression to the normal form (The problem is that i don't know how). And then, by De Moivre's formula I can find the roots.

Any idea on how to simplify the formula and reach the normal form?

Thank you! - Aug 12th 2010, 05:57 AMHallsofIvy
I think you might do better to use the "polar form", . That way

.

Put that last number into polar form: its magnitude is and its argument is [tex]arctan\left(-\frac{6\sqrt{2}}{12}\right)= arctan\left(-\sqrt{2}{2}}\right) .

Now solve and . The real and imaginary parts are and , respectively. - Aug 12th 2010, 10:14 AM11rdc11
Should it not be

- Aug 12th 2010, 10:19 AMyeKciM