Complex Math Question

That doesn't seem right. if N = A+iB then D = A-iB if I multiply top and bottom by A+iB I get (A+iB)^2/(A^2+B^2)

(Unless I didn't understand)

George H

Sure. Just convert to polar coordinates and it's clear.

A exp(j phi)

----------- == exp(j 2 phi) A exp(-j phi)

Cheers

Phil Hobbs

Duh, (Scuffs shoe in dirt, hangs head in shame.) George H.

Don't feel bad. I just proved it to myself by backing up to a sane expression....

(A-jB)/(A+jB)

and checking against the TAN(2x) expression.

I got myself balled-up with a messy complex expression (fitting an all-pass to specific angles).

...Jim Thompson

Well, the net phase angle _is_ twice the numerator's.

If it was simple, they wouldn't have called it "complex".

:-D ...Jim Thompson

Hello? Conjugate is just the number rotated 180o on the Argand diagram, angles subtract upon division, so quotient has angle twice the numerator. We don't need no stinking algebra to figure that one out.

I assume you mean Complex as in sqrt(-1), not Complex as in difficult. Rotating, charged colliding black holes are difficult, sums are not...

Kevin Aylward B.Sc.

Yes

:-D

...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at