Evaluate (5+5sqrt(3)i)^7 using DeMoivre’s theorem.
Write your answer in rectangular form. Show all your work.
First, place the problem in r·cis(theta) form.
r = sqrt( x2 + y2 ) = sqrt[ (5)2 + (5·sqt(3))2 ] = sqrt( 25 + 75 ) = sqrt(100) = 10
theta = tan-1( y / x ) = tan-1( 5·sqt(3) / 5 ) = 60o
[ 10·cis( 60o) ]7 = 107 · cis( 7·60o ) = ...
Is this the answer?
5000000+5000000isqrt(3)
was that the answer.