Question Number 171979 by Shrinava last updated on 22/Jun/22

Answered by puissant last updated on 23/Jun/22

$${sin}\theta+{icos}\theta=\frac{−{i}}{−{i}}\bullet{sin}\theta+{icos}\theta \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\:\frac{−{isin}\theta+{cos}\theta}{−{i}} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\:−\frac{{e}^{−{i}\theta} }{{i}} \\ $$