Units tex

Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\unit{}} Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\hertz{{\rm Hz}}} Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\kelvin{{\rm K}}} Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\metre{{\rm m}}} Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\reciprocal[1]{{#1}^{-1}}} Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\mega{{\rm M}}} Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\micro{\mu}} Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\kilo{{\rm k}}} Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\second{{\rm s}}} Failed to parse (unknown function "\newcommand"): {\displaystyle \newcommand\per{/}}