A Phasor is a [[Complex Numbers|Complex]] [[Function]] from the [[Real Numbers|reals]] to the [[Complex Plane|complex plane]] [[Sinusoidal Functions|sinusoidally]] (typically using the [[Complex Exponential]]).
$\huge \begin{align}
f: \R &\to \C\\
f(t) &= Ae^{i\omega t} \\
&=e^{\ln A + i \omega t} \\
&= re^{i\omega t}
\end{align}
$
Where $\omega$ is the [[Angular Frequency]] and $A$ is the [[Amplitude]].