A variable straight line of slope 4 intersects the hyperbola xy = 1 at two points. The locus of the point which divides the line segment between these two points in the ratio 1 : 2 is
Let P(h, k)
y - k = 4(x - h) --- (1)
Let it meets xy = 1 ----(2) at A (x1,y1) and B (x2,y2)
x1+x2=4h−k4,x1x2=−14 Also ⇒ ∴2x1+x23=h⇒x1=8h+k4,x2=2h+k2
⇒16x2+10xy+y2=2