Note : For the purposes of this animation, we are looking at the "vertical component" of the phaser vectors, so the equations for the voltages involve SINE functions - traditionally, you would use the "horiztonal component" and thus COSINE functions ... six of one, half dozen of the other ... in other words, as long as you are consistant, it doesn't matter! (In either case, the voltage values at a particular time still add up to the main voltage!).