Given the formula \vec{p}=\frac{m_0}{\sqrt{1-\frac{|\vec{v}|^2}{c^2}}}\vec{v}, I'd like to make \vec{v} the subject, so I can do a numerical approximation for some relativistic motion problem. I want to treat it as a vector equation, but since it is non-linear, the only way I can think of is to...