# Thread: Complex numbers - express in real and imaginary parts

1. ## Complex numbers - express in real and imaginary parts

Hello everyone
I've got a problem with these two questions:

Express the following complex numbers in real and imaginary parts :

z=6ln(1+j)

z=1/cos^2(1/2 j ln (j))

I'm completely stuck, any hints will be much appreciated.

2. ## Re: Complex numbers - express in real and imaginary parts

Suppose that

$a+jb \equiv re^{j(\theta+2k\pi)},$

then

$\ln(a+jb) = \ln (r) + j(\theta + 2k\pi).$

3. ## Re: Complex numbers - express in real and imaginary parts

Thanks a lot, I've got it sorted now.