“How can we represent AC current in vector form?”
We have a problem. AC current calculations can be drastically simplified if they are put into vector form. However, at the same time they are constantly changing. So how can we make a dynamic form for phasors? Well, let’s think about it. We know that the magnitude of the combination of the real and imaginary magnitudes of the current will be constant throughout. And we also know that these values of these separately will be constantly oscillating. So what if we were to represent these values with a cosine function and a frequency in order to emulate these properties? Well, these representations are known as phasors and are used for every part of AC circuit analysis.