$\mathrm {\int \dfrac{1}{\sqrt{5-x^{2}}} d x=?}$

$\mathrm {\sin ^{-1} \dfrac{x}{\sqrt{5}}+c}$

$\mathrm {\dfrac{1}{\sqrt{5}} \sin ^{-1} \dfrac{x}{\sqrt{5}}+c}$

$\mathrm {\tan ^{-1} \dfrac{x}{\sqrt{5}}+c}$

$\mathrm {\dfrac{1}{\sqrt{5}} \tan^{-1} \dfrac{x}{\sqrt{5}}+c}$