Q5. Form the differential equation of the family of circles in the first quadrant which touches the coordinate axes.
Now, the equation of the circle with center at (x,y) and radius r is
Since it touch the coordinate axes in the first quadrant
Therefore, a = b = r
-(i)
Differentiate it w.r.t x
we will get
-(ii)
Put value from equation (ii) in equation (i)
Therefore, the differential equation of the family of circles in the first quadrant which touches the coordinate axes is