The voltage-current relationship for the resistors, inductors, and capacitors can be transformed from the time domain to the phasor or frequency domain using phasor representation. In the time domain, Ohm's law provides a relation between the current flowing through a resistor and the voltage across it. Similarly, in phasor representation, the voltage and current are in phase and follow Ohm's law. For an inductor, the rate of change of current gives the voltage across it. The sinusoidal function is converted into its phasor in polar format. Comparing the current and voltage phasors, the current lags the voltage by 90 degrees. Using Euler's identity, the current-voltage relationship in the phasor domain is obtained. Similarly, when charging a capacitor, the rate of change of voltage determines the current passing through it, and the sinusoidal function is used to obtain its phasor in polar form. The phasor representations indicate that the current leads voltage by 90 degrees, and the relationship between current and voltage phasors can be obtained by substituting the time derivative of the voltage.