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OpenStudy (anonymous):
What are all the roots for r^4+1=0 and how do I find them?
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OpenStudy (anonymous):
A root is anywhere where a function is equal to zero. Your equation equals zero when:
\[r^4 = -1\]
Which has no real roots.
OpenStudy (anonymous):
What are the non real roots
OpenStudy (anonymous):
Have you covered complex numbers? Are you expected to give the complex roots?
OpenStudy (anonymous):
yeah
myininaya (myininaya):
\[r^4=\cos(\pi+2n \pi)+i \sin(\pi+2n \pi)\]
since cos(pi)=-1 and sin(pi)=0
the right hand side is still -1
since -1+0=-1
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myininaya (myininaya):
use demoirve's law (i think that is what it is called)
OpenStudy (anonymous):
The solution shows me radical2/2 +/- radical2/2 i; -rdicL2/2 =/- radical 2/2 i @myininaya but I'm not sure how to get those
myininaya (myininaya):
take the 4 root of both sides
OpenStudy (anonymous):
ohh right thank youuu!
myininaya (myininaya):
you would have one solution given by n=0
another by n=1
another by n=2
and the last by n=3
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myininaya (myininaya):
that is 4 solutions
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