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## #1 2005-09-20 14:19:11

notamathperson
Member
Registered: 2005-09-13
Posts: 5

### Imaginary Numbers

I understand my homework pretty well this time, but I do have a couple questions:

Simplify (√-4) x (√-8)
I ended up getting 2√8, but I'm not sure if this is correct

Also, can this number be simplified any more: (2+2i√14) / 6?
Specifically, can the square root be simplified or could it look something like this: (1+i√14) / 3?

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## #2 2005-09-20 15:28:28

kylekatarn
Member
Registered: 2005-07-24
Posts: 445

### Re: Imaginary Numbers

√(-4).√(-8) = √(4)i.√(8).i = 2√(8).i² = -2√(8) = -2√(2³) = -2√(2.2²) = -4√(2)

``````2 + 2i√14   2   2i√14   1   √14                   1+i√14
--------- = - + ----- = - + ---i  or, if you want ------
6       6     6     3    3                       3``````

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## #3 2005-09-20 15:36:19

notamathperson
Member
Registered: 2005-09-13
Posts: 5

### Re: Imaginary Numbers

Thanks Kyle, I appreciate it.

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## #4 2005-09-20 20:18:23

MathsIsFun
Registered: 2005-01-21
Posts: 7,664

### Re: Imaginary Numbers

Ohhh, multiplying negative square roots is a weird one.

Perhaps it should be:  ±4√(2)

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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