SOLUTION: z=r(cos theta + i sin theta) show: a) {z}=r b) 1/z = 1/r(cos theta - i sin theta)

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Question 384769: z=r(cos theta + i sin theta) show:
a) {z}=r
b) 1/z = 1/r(cos theta - i sin theta)
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
z=r(cos theta + i sin theta) show:
a) {z}=r
z = r(cos^2+sin^2)
= r*1
= r
---------------
b) 1/z = 1/r(cos theta - i sin theta)
That is an identity if z = r(cis(theta))
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What are you expected to show?
Cheers,
Stan H.