The locus of mid-points of points of intersection of $$x \cos \theta+y \sin \theta=1$$ with the coordinate axes is

Suppose $$P$$ and $$Q$$ lie on $$3 x+4 y-4=0$$ and $$5 x-y-4=0$$ respectively. If the mid-point of $$P Q$$ is $$(1,5)$$, then the slope of the line passing through $$P$$ and $$Q$$ is

The length of intercept of $$x+1=0$$ between the lines $$3 x+2 y=5$$ and $$3 x+2 y=3$$ is

Suppose that the three points $$A, B$$ and $$C$$ in the plane are such that their $$x$$-coordinates as well as $$y$$-coordinates are in GP with the same common ratio. Then, the points $$A, B$$ and $$C$$