^{13}Although A truly should represent a waveform’s peak value, and θ should be expressed in units of radians to be
mathematically correct, it is more common in electrical engineering to express A in RMS (root-mean-square) units and θ in
degrees. For example, a 120 volt RMS sine wave voltage at a phase angle of 30 degrees will be written by an engineer
as 120e^{j30} even though the true phase angle of this voltage is π
6 radians and the actual peak value is 169.7
volts.