## How do i find the principal form of this complex number

z= (10-j+elogj)2

I tried expanding but it just made it more complicated.

 PhysOrg.com science news on PhysOrg.com >> Front-row seats to climate change>> Attacking MRSA with metals from antibacterial clays>> New formula invented for microscope viewing, substitutes for federally controlled drug
 the principal form is defined in my book as ln(z)=ln(r)+jθ

Recognitions:
Homework Help
 Quote by iampaul z= (10-j+elogj)2 I tried expanding but it just made it more complicated. help please!!
Hi iampaul!

To find the principal form you need to find the length and the angle of z.
First step is to find the length and angle of 10-j.
And also of elogj.
Do you know how?

## How do i find the principal form of this complex number

How?
That's exactly what my problem is.
10-j and elogj
aren't similar to any of the forms discussed in school.
Can you give another hint?

 Recognitions: Homework Help Let's try and find ln(z)=ln(r)+jθ for 10-j and for elogj. ln(10-j) = -j ln(10) = ln(1) - j ln(10) So what is the length r and what is the angle θ for 10-j? Let's break elogj apart a little further. First we look at "j". Did you know that "j" has length 1 and angle pi/2? In other words, we have: $$j = e^{j {\pi \over 2}}$$ Can you take the log of j? And if so, find the length and angle of elogj?
 thanks!!