$\sin \tan ^{-1} \frac{a}{b}$ এর মান-

$\frac{a}{\sqrt{a^{2}+b^{2}}}$

$\frac{\sqrt{a^{2}+b^{2}}}{a}$

$\frac{b}{\sqrt{a^{2}+b^{2}}}$

$\frac{\sqrt{a^{2}+b^{2}}}{b}$