Question

What Ln(z) is answer????!!

Answer 1

Write z in exponential form:

`z=1-i=\sqrt2 e^(-i\frac\pi4)`

Then taking the logarithm, we get

`\mathrm{Ln}(z)=\ln(\sqrt2) + \ln e^(-i\frac\pi4) = \boxed{\ln(\sqrt2)-\frac\pi4i}`

so a is the correct answer.