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#1 2015-07-12 23:05:40

threep14rrr
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-i times i

Hi!

Help! I found on mathsisfun about Imaginary Numbers that -i times i equals 1. May anyone please prove?

Thanks

-rrr


Memorizing pi ain't no piece of PIe. You need to pray and have PIety, because it's an ePIc job.

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#2 2015-07-12 23:13:03

mathaholic
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Re: -i times i

I believe why -i * i equals 1 is because something like this: (-1)(-1)(1)(1) which is 1*1*1 which is 1. Just an assumption.

Last edited by mathaholic (2015-07-12 23:19:01)


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#3 2015-07-12 23:16:38

threep14rrr
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Registered: 2015-07-12
Posts: 109

Re: -i times i

Makes sense. I'll see.

Thanks!


Memorizing pi ain't no piece of PIe. You need to pray and have PIety, because it's an ePIc job.

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#4 2015-07-12 23:19:39

mathaholic
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Re: -i times i

No problem. Happy to help you. I've been here for almost 3 years.


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#5 2015-07-12 23:19:41

threep14rrr
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Registered: 2015-07-12
Posts: 109

Re: -i times i

But, does that mean -i is the answer to √1?


Memorizing pi ain't no piece of PIe. You need to pray and have PIety, because it's an ePIc job.

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#6 2015-07-12 23:26:50

zetafunc
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Re: -i times i

The imaginary unit is defined as i² = -1.

Help! I found on mathsisfun about Imaginary Numbers that -i times i equals 1. May anyone please prove?

(-i)*(i) = -(i*i) = -(i²) = 1.

But, does that mean -i is the answer to √1?

By convention:

√1 = 1, by convention. However, the equation x² = 1 has two solutions, 1 and -1.

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#7 2015-07-13 00:01:18

threep14rrr
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From: The country I made up.
Registered: 2015-07-12
Posts: 109

Re: -i times i

Now I see. Thanks! smile


Memorizing pi ain't no piece of PIe. You need to pray and have PIety, because it's an ePIc job.

Progress-120

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