Question Number 147762 by DomaPeti last updated on 23/Jul/21
$${how}\:{to}\:{minimalize}\:{t}? \\ $$$$\underset{{x}_{\mathrm{2}} } {\overset{{x}_{\mathrm{1}} } {\int}}\frac{\sqrt{\mathrm{1}+\left({y}\left({x}\right)'\right)^{\mathrm{2}} }}{\:\sqrt{{x}^{\mathrm{2}} +{y}\left({x}\right)^{\mathrm{2}} }\centerdot{c}_{\mathrm{1}} +{c}_{\mathrm{0}} }\Delta{x}={t} \\ $$$$ \\ $$