- #1
msimard8
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Homework Statement
find all complex roots of z^8=81i
Homework Equations
The Attempt at a Solution
let the angle=x
z^8=r^8(cis8x)
we know
81i=81 (cis pi/2)
threfore
z^8=81(cos pi/2 + i sin (pi/2) )
8x= pi/2 + 2kpi
x = pi/16 + kpi/4 kEz
therefore
if k=1 z=sqrt3 (cis pi/16)
i go through this solutiosn...and should end up getting a result angle of pi/2 in one of them..becuse on of the roots is 1...so there i must be wrong..help