Question Number 53779 by maxmathsup by imad last updated on 25/Jan/19
$$\Sigma\:{u}_{{n}} {is}\:{a}\:{convergent}\:{serie}\:\left({u}_{{n}} >\mathrm{0}\right)\:\:{find}\:{nature}\:{of}\:{the}\:{serie} \\ $$$$\left.\mathrm{1}\right)\:\Sigma\:\frac{\sqrt{{u}_{{n}} }}{{n}} \\ $$$$\left.\mathrm{2}\right)\Sigma\:\:\frac{{u}_{{n}} }{\mathrm{1}+{u}_{{n}} } \\ $$