I'm sure my question is very simple to most of u guys. But I have the following confusion. Let's say we have an AC voltage source in a circuit. In rectangular form it's phasor form is v= -4 - 16 j . I want to write this phasor in polar form. Well, The phasor is in 3rd quadrant of complex plane. It's magnitude comes out to be 16.49 For phase angle, [tex]\phi[/tex] = arctan (-16/-4) = 75.96◦ To shift 75.96 degrees from 1st quadrant to 3rd quadrant I can approach in 2 ways. like [tex]\phi[/tex] = 75.96+ 180 = 255.96◦ or, [tex]\phi[/tex] = 75.96- 180 = -104.04◦ Thereby in polar form, v can be written like either v= 16.49[tex]\angle255.96[/tex] or, v= 16.49[tex]\angle-104.04[/tex]. From mathematical point of view both the polar forms of v are ok. My question is that from electrical engineering viewpoint which polar form is to be written i.e. which phase angle is preferred in practice 255.96◦ or -104.04◦?