- #1
trap101
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Homework Statement
Find both square roots of the following number:
-15-8i
Homework Equations
De Moivre's thm: rn(cos(n[itex]\sigma[/itex]) + i sin(n[itex]\sigma[/itex])
The Attempt at a Solution
So to use De Moivre's I have to find the modulus and the argument.
actually in this question r = 1, what I'm left to have to try and figure out is how to obtain -15 - 8i
from (cos(n[itex]\sigma[/itex]) + i sin(n[itex]\sigma[/itex])
All I could think of possibly doing is setting Cos[itex]\sigma[/itex] = -15 and
iSin[itex]\sigma[/itex] = -8 but even doing that doesn't really provide me with much information. Unless that's what I'm suppose to work with.