Maths - OL - Complex Numbers help

Finical · 2010-06-07 15:44:16

Just got one question from 2006 4(b)(ii) Write in its simplest form: i(i^4+i^5+i^6) I looked at the answer on examinations.ie, but I haven't a clue how they managed it. Could someone please help and show how they get the figures in layman's terms. :pac:

07-06-2010 04:44PM

#1

Finical

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Just got one question from 2006 4(b)(ii) Write in its simplest form: i(i^4+i^5+i^6)

I looked at the answer on examinations.ie, but I haven't a clue how they managed it. Could someone please help and show how they get the figures in layman's terms. :pac:

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#2 07-06-2010 04:50PM

SYLT

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-1. I think.

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#3 07-06-2010 04:55PM

MariaBabii

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i(i4 + i5 + i6) = i5 + i6 + i7 = i(i4) + i2(i4) + i3(i4) = i + (-1) + (-i) = -1

in the sum .. i4 is the equivalent to 1 (i4=1)

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#4 07-06-2010 04:57PM

Reillyman

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[latex] i(i^4+i^5+i^6)[/latex]

[latex]= i^5+i^6+i^7[/latex]

[latex]= i-1-i[/latex]

[latex]= -1[/latex]

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#5 07-06-2010 04:59PM

Emmpty

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i^4=1
i^5=i
i^6=-1
so the bracket added up is i
i x i = i^2
which equals -1

You just have to break it down for yourself.

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#6 07-06-2010 05:09PM

Finical

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Thanks a mill everyone, sorted now.

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