Q.

Let the director circle of the hyperbola H:x2a2-y2b2=1  (a>b) be denoted by C1 and let director circle of ellipse E:x2a2+y2b2=13  (a>b) be denoted by C2 and C2 is also the director circle of C1 and let e1 and e2 be the eccentricities of the ellipse E and hyperbola H respectively. Then e22e12 is equal to

1 18  
2 12  
3 6  
4 24  

Ans.

(3)

Ortho-centres of triangles formed by three tangents and corresponding normal to a parabola are equidistant from axis of parabola.