The equation $$r\,\cos \left( {\theta - {\pi \over 3}} \right) = 2$$ represents

Let each of the equations x² + 2xy + ay² = 0 and ax² + 2xy + y² = 0 represent two straight lines passing through the origin. If they have a common line, then the other two lines are given by

A straight line through the origin O meets the parallel lines 4x + 2y = 9 and 2x + y + 6 = 0 at P and Q respectively. The point O divides the segment PQ in the ratio

A line cuts the X-axis at A(7, 0) and the Y-axis at B(0, $$ - $$5). A variable line PQ is drawn perpendicular to AB cutting the X-axis at P(a, 0) and the Y-axis at Q(0, b). If AQ and BP intersect at R, the locus of R is