If the straight line 4y-3x+18=0 cuts the parabola `y^(2)=64x` in P&Q then the angle subtended by PQ at the vertex of the parabola is

A double ordinate of the parabola y^(2)=8px is of length 16p. The angle subtended by it at the vertex of the parabola is

The straight lines y=+-x intersect the parabola y^(2)=8x in points P and Q, then length of PQ is

If the line y-sqrt(3)x+3=0 cuts the parabola y^(2)=x+2 at P and Q then AP.AQ is equal to

Find the locus of the middle points of the chords of the parabola y^(2)=4ax which subtend a right angle at the vertex of the parabola.

If the straight line 3x+4y+1=0 is a normal to the parabola y^(2)+lambda x=0 ,then distance between focus and directrix of the parabola is

If the segment intercepted by the parabola y^(2)=4ax with the line lx+my+n=0 subtends a right angle at the vertex then:

The radius of the circle whose centre is (-4,0) and which cuts the parabola y^(2)=8x at A and B such that the common chord AB subtends a right angle at the vertex of the parabola is equal to