Form the differential equation of all concentric circles at the origin.

Form the differential equation of family of lines concurrent at the origin.

The differential equation of all circles with centre at the origin is ………

Form the differential equation of the family of circles in the second quadrant and touching the coordinate axes.

Form the differential equation of all circle touching the x-axis at the origin and centre on the y-axis.

Form the differential equation of the family of circles touching the x-axis at origin.

Form the differential equation of all straight lines touching the circle x^(2)+y^(2)=r^(2).

Form the differential equation of the family of circles in the first quadrant which touch the coordinate axes.

Form the differential equation of the family of circles having centre on y -axis and radius 5 units.