HCU MCA 2013 Paper

(c) Given, $\mathrm{S}=2^{\mathrm{n}}+3^{\mathrm{n}}$
For n = 1,
$\mathrm{S}=2^{\mathrm{1}}+3^{\mathrm{1}}=5$
It is not a square of rational number.
For n = 2,
$\mathrm{S}=2^{\mathrm{2}}+3^{\mathrm{2}}=4+9=13$
It is not a square of rational number.
For n = 3,
$\mathrm{S}=2^{\mathrm{3}}+3^{\mathrm{3}}=8+27=35$
It is not a square of rational number.
For n = 4,
$\mathrm{S}=2^{\mathrm{4}}+3^{\mathrm{4}}=16+81=97$
It is not a square of rational number,