If a normal chord at a point t( 0) on the parabola y^2=9 x subtends a right angle at its vertex, then t=

Step-by-step solution

Equation of given parabola is Equation of normal chord at a point t( 0) on the parabola (i) is The chord (ii) subtends a right angle at vertex of parabola V(0,0) , so first homogenise the parabola (i) with the help of line (ii), we get array rlrl & So, & 1- 9 t 9 2 t+ 9 4 t^3 & =0 & 1- 1 1 2 + t^2 4 & =0 & 1 2 + t^2 4 & =1 & t^2=2 t & = 2 array Hence, option (d) is correct.