Harmonics (electrical power)
Total harmonic distortion

T H D V = V 2 2 + V 3 2 + V 4 2 + ⋯ + V n 2 V 1 ⋅ 100 % = ∑ k = 2 n V k 2 V 1 ⋅ 100 % T H D I = I 2 2 + I 3 2 + I 4 2 + ⋯ + I n 2 I 1 ⋅ 100 % = ∑ k = 2 n I k 2 I 1 ⋅ 100 % {\displaystyle {\begin{alignedat}{3}{\mathit {THD}}_{\mathrm {V} }&={\frac {\sqrt {V_{2}^{2}+V_{3}^{2}+V_{4}^{2}+\cdots +V_{n}^{2}}}{V_{1}}}\cdot 100\%&&={\frac {\sqrt {\sum _{k\mathop {=} 2}^{n}V_{k}^{2}}}{V_{1}}}\cdot 100\%\\{\mathit {THD}}_{\mathrm {I} }&={\frac {\sqrt {I_{2}^{2}+I_{3}^{2}+I_{4}^{2}+\cdots +I_{n}^{2}}}{I_{1}}}\cdot 100\%&&={\frac {\sqrt {\sum _{k\mathop {=} 2}^{n}I_{k}^{2}}}{I_{1}}}\cdot 100\%\end{alignedat}}}
oulipo:avoid_letter[o], detectable_content:postscript