Question

7) Use De Moivres theorem and simplify the
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Answer 1

Answer:

cos2theta+isin2theta

Step-by-step explanation:

by De Movers theorem

cosx+isinx= e^(ix)

(cos2theta+isin2theta)^7 / (cos4theta+isin4theta)^3

=(e^(i2theta))^7 / (e^(i4theta))^3

=e^(i14theta) / e^(i12theta)

=e^(i14theta -i12theta)

=e^(i2theta)

=cos2theta+isin2theta