We normally use this thing called the principal argument, such that all arguments are within
Can you see why these values have been used now? You're technically correct in your thinking and the angles are accurate; it's just something of a convention.
Last edited by Jam'; 14-07-2012 at 15:37.
The argument could be what you suggest or what is posted. The argument of z is simply the angle from the positive x axis. You could say an argument is pi/2, or you could say an argument is -3pi/2, because that would give you the same angle.
I have been taught to do it your way, and have a positive angle between 0 and 2pi. However, the approach shown is not incorrect.
It's pretty much just a matter of style or a convention. Like (sinx)^2 is normally written as sin^2 (x). Neither is wrong, and they both mean exactly the same thing, but one is simply more common.
Last edited by Llewellyn; 14-07-2012 at 15:33.