Friday, 16 March 2018

trigonometry - Use of de Moivre's Theorem and Euler's formula to solve an expression




Let n be a natural number, the Show that (cos(2)+isin(2)+1)n=2ncosn(1)(cos(n)+isin(n))



The use of Euler's formula and de Moivre's Theorem isn't succeeding. Does anyone have a hint for how I should proceed?



EDIT: Thank you all. There was a typo in the textbook, which is why I was struggling.


Answer



2ncosn(1)(cos(n)+isin(n))=2ncosn(1)(cos(1)+isin(1))n=(2cos(1)cos(1)+i2cos(1)sin(1))n=(2cos2(1)+isin(2))n=(cos(2)+isin(2)+1)n



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