9.3 Phasor (4)
• Transform a sinusoid to and from the time
domain to the phasor domain:

 (time domain)      (phasor domain)
• Amplitude and phase difference are two principal
concerns in the study of voltage and current sinusoids.
• Phasor will be defined from the cosine function in all our
proceeding study. If a voltage or current expression is in
the form of a sine, it will be changed to a cosine by
subtracting from the phase.