Triangles and Inequalities I

A Straight Line through the vertex $P$ of a triangle $PQR$ intersects the side $QR$ at the point $S$ and the circumcircle of the triangle $PQR$ at the point $T$ .If $S$ is not the centre of the circumcircle then..

$\frac { 1 }{ PS } +\frac { 1 }{ ST } >\frac { \eta }{ QR }$

Find $\eta$ ..