Mathematics
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OpenStudy (anonymous):
Explain why i^3=-i. What does i^4 equal?
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OpenStudy (anonymous):
i^4=i^3*i=-i*i=-i^2=-(-1)=1
OpenStudy (anonymous):
I dont undertand how though
OpenStudy (gw2011):
i^2=-1
(i^2)(i)=(-1)(i)=-i
i^4=(i^2)(i^2)=(-1)(-1)=1
OpenStudy (amistre64):
you ever tell time by a clock?
OpenStudy (anonymous):
yea
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OpenStudy (amistre64):
this is just clock addition .... but it only has 4 hours around it
OpenStudy (amistre64):
i is at 12 oclock; i^2 is at 3oclock; i^3 at 6 oclock; and i^4 at 9 oclock.
does that make sense?
OpenStudy (anonymous):
amistre64 u shud try sayin the unit circle...
OpenStudy (amistre64):
unit circle is an advanced concept, but yes :)
OpenStudy (amistre64):
like this
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OpenStudy (amistre64):
the reason it changes between is and 1s is that it is actually rotating thru the complex plane;
OpenStudy (anonymous):
amistre64 can u give some of u r medals to me? :D lol
OpenStudy (amistre64):
sure lol
OpenStudy (anonymous):
ya rotation is e^(i\theta)
OpenStudy (amistre64):
theres 1 :)
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OpenStudy (anonymous):
thnx...
OpenStudy (amistre64):
if you know how a clock moves from 9 to 3 by adding 6 hours; then this should be easy enough to understand
OpenStudy (amistre64):
its also known as modular addition