Phasors are complex representations of the sinusoids where the magnitude of the phasor equals the amplitude, and the angle equals the phase measured from the positive x-axis. They simplify the analysis of AC circuits by eliminating the time dependence of the current and voltage, transforming the circuit into its equivalent DC form. Phasors can be represented in rectangular, polar, or exponential forms by using Euler's identity. To obtain the phasor of a sinusoid in the sine form, first convert it into cosine form and then express it as the real part of the complex number. The phasor of this sinusoid equals the time-independent part of the complex number. Conversely, the sinusoid of a given phasor is obtained by multiplying the phasor with the time factor and taking its real part. Phasors can be represented as rotating vectors or sinors in a counterclockwise direction on a complex plane with a constant angular frequency, and the diagrams depicting them are known as phasor diagrams. The projection of the rotating sinors on the real axis represents the sinusoids.