How to find the Im: z, when #z=((1+i)/(1-i*sqrt(3)))^(-2i)#?

1 Answer
Mar 10, 2017

The imaginary component is

#sin(2log(2sqrt(2)))e^(2phi)# with #phi=arctan((1 + sqrt[3])/(1 - sqrt[3]))#

Explanation:

#(1+i)/(1-isqrt3)=(1+i)(1+isqrt3)/4=1/4(1-sqrt3+i(1+sqrt3))#

Now we will reduce this complex number to the exponential form by making

#x+iy=sqrt(x^2+y^2)e^(iphi)# where #phi=arctan (y/x)#

so making #x = 1-sqrt3# and #y=1+sqrt3# we have

#sqrt(x^2+y^2)=2sqrt2# and #phi=arctan((1 + sqrt[3])/(1 - sqrt[3]))#

now proceeding

#((1+i)/(1-isqrt3))^(-2i)=(2sqrt2)^(-2i)(e^(iphi))^(-2i)=(e^lambda)^(-2i)(e^(iphi))^(-2i)=e^(-2ilambda)e^(2phi)#

Here #lambda# is such that #e^lambda=2 sqrt2# or #lambda=log(2 sqrt2)#

Finally, using de Moivre's identity

#e^(ix)=cosx+isinx# we arrive at

#((1+i)/(1-isqrt3))^(-2i)=(cos(2log(2sqrt2))+isin(2log(2sqrt(2))))e^(2phi)#

and the imaginary component is

#sin(2log(2sqrt(2)))e^(2phi)# with #phi=arctan((1 + sqrt[3])/(1 - sqrt[3]))#