Question Number 133120 by abdomsup last updated on 19/Feb/21
$${calculate}\:{A}_{{n}} =\:\int\int_{\left[\frac{\mathrm{1}}{{n}},{n}\left[\right.\right.} \:\:\frac{{e}^{−{x}^{\mathrm{2}} −{y}^{\mathrm{2}} } }{\:\sqrt{{x}^{\mathrm{2}} +{y}^{\mathrm{2}} +\mathrm{3}}}{dxdy} \\ $$$${and}\:{lim}_{{n}\rightarrow\infty} {A}_{{n}} \\ $$