and

De Moivres states

which leads to

can be written

The two lines equals eachother if

and

making the angles

This is my problem:

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- January 30th 2009, 05:31 AMGreenbSolving an equation with de Moivre's formula

and

De Moivres states

which leads to

can be written

The two lines equals eachother if

and

making the angles

This is my problem:

- January 30th 2009, 06:34 AMSoroban
Hello, Greenb!

Is this the problem?

Quote:

. .Find

Code:`*`

: * 169

120 : *

: * θ

- - + - - - * - - - -

-119

We have: .

And we want: . .[1]

Using half-angle identities:

. .

. .

Substitute into [1]: .

- January 30th 2009, 08:43 AMGreenb
Ah I forgot that |z| equals the hypotenuse, but I'm not with you all the way on the half angle identities part, seeing that its a cubicequation, it should have two roots.

And what if the equation was;

could it be solved the same way?

I'm Swedish by the way so sorry if I don't get the termonoligy right.