In the chapter we shall develop a method for representing a sinusoidal forcing function or a sinusoidal response by a complex number called a phasor transform,or simply a phasor. By working with phasors we shall effect a truly remarkable simplification in the steady state sinusoidal analysis of general circuits
In the chapter we shall introduce the study of circuits characterized by a single energy-storage element--a capacitor or a inductor. It will be shown that the equations describing such a circuit may be put in a form involving an unknown variable and its first derivative. Such an equation is referred to as a first-order differential equation, thus we shall refer to circuits which contain only a single energy-storage element as first-order circuits