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Mathematics
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OpenStudy (anonymous):
i^-13
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OpenStudy (lgbasallote):
hint:
\[\large i^1 = i\]
\[\large i^2 = -1\]
\[\large i^3 = i^2 \times i - -1 \times i = -i\]
\[\large i^4 = (i^2)^2 = (-1)^2 = 1\]
\[\large i^5 = i\]
so the process repeats
does that help?
OpenStudy (anonymous):
it is raised to a negative number though. how does that work?
OpenStudy (lgbasallote):
simple..change it first to \[\huge \frac{1}{i^{13}}\]
OpenStudy (anonymous):
I was told to always go with the i^4 so what I have so far is:
1/(i^4)^3i=1/i
OpenStudy (lgbasallote):
that's right
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OpenStudy (anonymous):
so then how is the answer -i, is it the reciprocal?
OpenStudy (lgbasallote):
maybe you mean \[i^{-1}?\]
OpenStudy (anonymous):
oh no I'm confused now. LOL. how did you get i^-1
OpenStudy (lgbasallote):
\[i^{-1} = \frac 1i\]
OpenStudy (anonymous):
then how is the answer expected to be -i? I have the answer sheets for my review, I just don't know how she got to -i, when I keep getting 1/i
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OpenStudy (lgbasallote):
are you sure the question is \[\huge i^{-13}\] maybe it's \[\huge -i^{13}\]
OpenStudy (lgbasallote):
\[\huge i^{-13} = \frac 1i\]
\[\huge -i^{13} = -i\]
OpenStudy (lgbasallote):
uhmm wait...
OpenStudy (anonymous):
I'm waiting. lol.
OpenStudy (lgbasallote):
OHHH i see
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OpenStudy (lgbasallote):
\[\huge \frac 1i \implies \frac 1i \times \frac ii \implies \frac{i}{i^2}\implies \frac{i}{-1} \implies -i\]
it's rationalization
OpenStudy (lgbasallote):
how could i forget =))
OpenStudy (lgbasallote):
did you get what i did?
OpenStudy (anonymous):
BRILLIANT!!!!!! Thanks a million.
OpenStudy (lgbasallote):
welcome ^_^ just remember to do that everytime there's an i in the denominator
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