Step-by-step explanation:
[tex]m(x) = \frac{x}{1 + {x}^{2} } \\ \\ m( \frac{1}{x} ) = \frac{ \frac{1}{x} }{ \frac{ {1}}{ {x}^{2} } + 1} \times \frac{ {x}^{2} }{ {x}^{2} } = \frac{x}{1 + {x}^{2} } = m(x)[/tex]
m(1/x) = m(x)