JEE Advance - Mathematics (1988 - No. 25)
The equations of the tangents drawn from the origin to the circle $${x^2}\, + \,{y^2}\, - \,2rx\,\, - 2hy\, + {h^2} = 0$$, are
x = 0
y = 0
$$({h^2}\, - \,{r^2})\,x - \,\,2rhy\, = \,0$$
$$({h^2}\, - \,{r^2})\,x + \,\,2rhy\, = \,0$$