¹³Although 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.