(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

This problem is probably quite simple for people who have covered this topic but the answer for part A is n=4k where k is any integer.

Part B answer is n= 2+4k

Look below for the working out and i will tell you what i dont understand

2. Relevant equations

de moivres theorem

3. The attempt at a solution

polar form is ([itex]\sqrt{2}[/itex] cis [itex]\pi[/itex] /4)^n

so [itex]\sqrt{2}[/itex]^n [cos(n[itex]\pi[/itex] /4)] +isin(n[itex]\pi[/itex] /4)] (demoivres theorem)

When Sin (n[itex]\pi[/itex] /4) = 0 the equation is real

n[itex]\pi[/itex] /4 = 0 +k2[itex]\pi[/itex] (For some reason this should be +k[itex]\pi[/itex] which is why i dont get the answer.

n=8k (solving for n)

Part b is prety much the same thing but cos (n[itex]\pi[/itex] /4) The question that i am asking is why is it +k[itex]\pi[/itex] and not +k2[itex]\pi[/itex] as that is usually the period for sin and cosine but [itex]\pi[/itex] is the period for tan i know that.

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# Homework Help: Kpi or k2pi?

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