Can someone help me with this one?

Find the real and complex solution of the equation x[squared]-8=0.

Possible answers:

1. -2, 2, 2cis(pi/3)

2. 2, 2cis(2pi/3), 2cis(4pi/3)

3. -2, 2cis(pi/3), 2cis(2pi/3)

4. 2cis(pi/3), 2cis(2pi/3), 2cis(4pi/3)

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- Jan 13th 2007, 10:11 PMmike1Real and complex solutions
Can someone help me with this one?

Find the real and complex solution of the equation x[squared]-8=0.

Possible answers:

1. -2, 2, 2cis(pi/3)

2. 2, 2cis(2pi/3), 2cis(4pi/3)

3. -2, 2cis(pi/3), 2cis(2pi/3)

4. 2cis(pi/3), 2cis(2pi/3), 2cis(4pi/3) - Jan 14th 2007, 12:20 AMCaptainBlack
Are you sure that you have typed the question correctly. the only solutions

of $\displaystyle x^2-8=0$, are $\displaystyle x=\pm \sqrt{8}$.

From the list of solutions I would guess you are asked for the solutions of:

$\displaystyle x^3-8=0$,

in which case the answer will be 2, which you can check by cubing each of

the solutions in the lis to check that they come to 8.

RonL - Jan 14th 2007, 12:36 AMticbol
- Jan 14th 2007, 03:25 AMmike1
Now I'm really confused. Do you really think my worksheet is wrong?

- Jan 14th 2007, 04:33 AMCaptainBlack