MEDIUM
JEE Advanced
IMPORTANT
Earn 100

The vertex A of a parabola is joined to any point P on the curve y2=4ax and PQ is drawn at right angles to AP to meet the axis in Q. Prove that the projection of PQ on the axis is always equal to the latus rectum.

Important Questions on Conic Sections. The Parabola

MEDIUM
JEE Advanced
IMPORTANT
If on a given base(x-axis), a triangle is described such that the sum of the tangents of the base angles is constant, prove that the locus of the vertices is a parabola.
HARD
JEE Advanced
IMPORTANT
A double ordinate of the curve y2=4px is of length 8p. Prove that the lines from the vertex to its two ends are at right angles.
HARD
JEE Advanced
IMPORTANT
Two parabolas have a common axis and concavities in opposite directions. If any line parallel to the common axis meets the parabolas in P and P', prove that the locus of the middle point of PP' is another parabola, provided that the latus rectum of the given parabolas are unequal.
MEDIUM
JEE Advanced
IMPORTANT
A parabola is drawn to pass through A and B, the ends of a diameter of a given circle of radius a, and to have as directrix a tangent to a concentric circle of radius b; the axis being AB and a perpendicular diameter, prove that the locus of the focus of the parabola is
x2b2+y2b2-a2=1.
MEDIUM
JEE Advanced
IMPORTANT
The equations of the tangent and the normal at the point 4, 6 of the parabola y2=9x are cy-3x=d & 3y+ax=b, respectively. Find a+b+c+d.
MEDIUM
JEE Advanced
IMPORTANT
The equations of the tangent and the normal at the point of the parabola y2=6x, whose ordinate is 12 are 4y-ax=b & y+cx=d, respectively. Find a+b+c+d.
MEDIUM
JEE Advanced
IMPORTANT
At the ends of the latus rectum of the parabola y2=12x, the equations of tangents are x+y=p & x-y=q and equations of the normals are x+y=r & x-y=s, where p, q, r, s are integers. Find p+q+r+s.
MEDIUM
JEE Advanced
IMPORTANT
At the ends of the latus rectum of the parabola y2=4ax-a, the equations of tangents are x+y=pa & x-y=qa and equations of the normals are x+y=ra & x-y=sa, where p, q, r, s are integers. Find p+q+r+s.