Let the point, on the line passing through the points $P(1,-2,3)$ and $Q(5,-4,7)$, farther from the origin and at a distance of $9$ units from the point $\mathrm{P}$, be $(\alpha, \beta, \gamma)$. Then $\alpha^2+\beta^2+\gamma^2$ is equal to :
→Diffrential coefficient of ${\left( {{x^{\frac{{\ell \, + \,m}}{{m\, - \,n}}}}} \right)^{\frac{1}{{n\, - \,\ell }}}}\,\,\,\,.\,\,\,\,{\left( {{x^{\frac{{\,m + \,n}}{{n\, - \,\ell }}}}} \right)^{\frac{1}{{\,\ell \, - \,m}}}}\,\,\,.\,\,\,{\left( {{x^{\,\frac{{n\, + \,\ell \,}}{{\ell \,\, - \,\,m}}}}} \right)^{\frac{1}{{m\, - \,n\,}}}}\,$ w.r.t. $x$ is
→The function defined by $f(x)\, = \,\left\{ {\begin{array}{*{20}{c}}{{{\left( {{x^2} + {e^{\frac{1}{{2 - x}}}}} \right)}^{ - 1}}}&,&{x \ne 2}\\k&,&{x = 2}\end{array}} \right.$, is continuous from right at the point $x = 2$, then $k$ is equal to
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