Mathematics - Parabola Question with Solution | TestHub

Through the vertex O of the parabola $y^2=4ax$ two chords OP \& OQ are drawn and the circles on OP \& OQ as diameter intersect in R. If ${\theta }_1,{\theta }_2\&\varphi$ are the inclinations of the tangents at $\mathrm{P}\&\mathrm{Q}$ on the parabola and the line through $\mathrm{O},\mathrm{R}$ respectively, then the value of $\cot {\theta }_1+\cot {\theta }_2$ is