= Solution
For this question use <phasors> with time factor $e^{i\omega t}$, so an <electrical impedance> is $Z=\widetilde V/\widetilde I$. The same <electric current> flows through all components of a <series circuit>, and their <voltages> add by <Kirchhoff's voltage law>. Hence the total series <electrical impedance> is
$$
\boxed{Z_{\mathrm{series}}=R+i\left(\omega L-\frac1{\omega C}\right).}
$$
The individual steady sinusoidal currents and their phase relations are derived in the following three parts. The diagram normalizes each current by its own amplitude, so it compares <phase differences> without mixing unlike physical units.
\Image[/past-exam-of-the-physics-2-paper-of-the-university-of-oxford/2018-component-waveforms.png]
{title=Normalized voltage and current waveforms for a <resistor>, <capacitor> and <inductor>; capacitor current leads and inductor current lags by a quarter cycle}
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