Question -
Answer -
It is given that thecentre lies on the positive y – axis at a distance of 6 from the origin, we getthe centre (0, 6).
We have a circle withcentre (0, 6) and having radius 4.
We know that theequation of the circle with centre (p, q) and having radius ‘r’ is given by: (x– p)2 + (y – q)2 = r2
Where, p = 0, q = 6, r= 4
Now by substitutingthe values in the equation, we get
(x – 0)2 +(y – 6)2 = 42
x2 + y2 –12y + 36 = 16
x2 + y2 –12y + 20 = 0.
∴ The equation of thecircle is x2 + y2 – 12y + 20 = 0.