Question Number 35625 by abdo mathsup 649 cc last updated on 21/May/18
$${find}\:{lim}_{\xi\rightarrow\mathrm{0}} \:\:\:\:\int_{\mathrm{0}} ^{\frac{\pi}{\mathrm{2}}} \:\:\:\:\:\:\frac{{dx}}{\:\sqrt{\:{sin}^{\mathrm{2}} {x}\:+\xi\:{cos}^{\mathrm{2}} {x}}} \\ $$