JEE Math Practice Question

Consider the hyperbola \[ \frac{x^{2}}{100}-\frac{y^{2}}{64}=1 \] with foci at $S$ and $S_{1}$, where $S$ lies on the positive $x$-axis. Let $P$ be a point on the hyperbola, in the first quadrant. Let $\angle S P S_{1}=\alpha$, with $\alpha<\frac{\pi}{2}$. The straight line passing through the point $S$ and having the same slope as that of the tangent at $P$ to the hyperbola, intersects the straight line $S_{1} P$ at $P_{1}$. Let $\delta$ be the distance of $P$ from the straight line $S P_{1}$, and $\beta=S_{1} P$. Then what is the greatest integer less than or equal to $\frac{\beta \delta}{9} \sin \frac{\alpha}{2}$?