Let z_1=2[cos(pi/6)+isin(pi/6)] How do you find 1/z_1?

1 Answer
Dec 5, 2016

1/z_1=sqrt3/4-i1/4

Explanation:

1/(z_1)=z_1^-1

using De'Moivre's theorem

1/z_1=z_1^-1=[2(cos(pi/6)+isin(pi/6))]^-1

1/z_1=z_1^-1=[2^-1(cos(-pi/6)+isin(-pi/6))]

costheta is an even function;""sintheta an odd one#

1/z_1=z_1^-1=[1/2(cos(pi/6)-isin(pi/6))]

1/z_1=z_1^-1=[1/2(sqrt3/2-i1/2)]

1/z_1=sqrt3/4-i1/4