Phasor diagram (complex plane) with the y-axis as imaginary part and x-axis as real part of a complex number. As an example, the complex resistance of a coil $$Z_{\text L} = i \, \omega \, L$$ (complex part only), the ohmic resistance $$Z_{\text R} = R$$ and the complex resistance of a capacitor $$Z_{\text C} = -\frac{i}{\omega \, C}$$ are shown. Vector addition of the three complex numbers yields the complex total resistance $$Z$$.