esempio
\[x = {-b \pm \sqrt{b^2-4ac} \over 2a}.\]
prova formula percorso
\[\sqrt{PP} = \sqrt{E^2 \over c^2 - p^2} = \sqrt{(mγc)^2 - (mγv)^2 } = mγ\sqrt{1-β^2c}=mc.\]
\sqrt{PP}= \sqrt{\frac{E^{2}}{c^{2}-p^{2}}}= \sqrt{(m\gamma c)^{2}-(m\gamma v)^{2}}= m\gamma \sqrt{1-\beta ^{2}c}= mc
\[\sqrt{PP}= \sqrt{\frac{E^{2}}{c^{2}-p^{2}}}= \sqrt{(m\gamma c)^{2}-(m\gamma v)^{2}}= m\gamma \sqrt{1-\beta ^{2}c}= mc\]