If $$(2,3,-1)$$ is the foot of the perpendicular from $$(4,2,1)$$ to a plane, then the equation of the plane is

The octant in which the point (2, $$-$$4, $$-7$$) lies is

The coordinates of foot of the perpendicular drawn from the origin to the plane $$2 x-3 y+4 z=29$$ are

The angle between the pair of lines $$\frac{x+3}{3}=\frac{y-1}{5}=\frac{z+3}{4}$$ and $$\frac{x+1}{1}=\frac{y-4}{4}=\frac{z-5}{2}$$ is