Answer
$$\frac{4}{3} $$
Work Step by Step
Assume that $\sin\theta =\frac{8}{10}$, then by solving the triangle, we have:
$$\tan \theta=\frac{8}{6}=\frac{4}{3}.$$
Now, since $\theta =\sin^{-1}\frac{8}{10} $, we have
$$\tan(\sin^{-1}\frac{8}{10} )=\tan\theta=\frac{4}{3} .$$
