The normals at three points· P,Q and R of the parabola y2 = 4ax meet at (h, k). The centroid of the PQR lies on
x = 0
y = 0
x = - a
y = a
A tower AB leans towards West making an angle with the vertical. The angular elevation of B, the top most point of the tower is as observed from a point C due East of A at a distance 'd' from A. If the angular elevation of B from a point D due East of C at a distance 2d from C is r, then 2 can be given as
P is a fixed point (a, a, a) on a line through the origin is equally inclined to the axes, then any plane through P perpendicular to Op, makes intercepts on the axes, the sum of whose reciprocal is equal to
a
None of these
The tangent at (1, 7) to the curve x2 = y - 6 touches the circle x2 + y2 + 16x + 12y + c = 0 at
(6, 7)
(- 6, 7)
(6, - 7)
(- 6, - 7)
In an equilateral triangle, the inradius, circumradius and one of the exradii are in the ratio
2 : 3 : 5
1 : 2 : 3
1 : 3 : 7
3 : 7 : 9
Y-axis cuts the line joining the points (- 3, - 4) and (1, - 2) in the ratio
1 : 3
2 : 3
3 : 1
3 : 2
C.
3 : 1
If the points (1, 1), (- 1, - 1), are the vertices of a triangle, then this triangle is
a right-angled triangle
an isosceles triangle
an equilateral triangle
None of the above
The point of intersection of the lines and is
(2, 10, 4)
(21, 5/3, 10/3)
(5, 7, - 2)
(- 3, 3, 6)