Question

Find the centre and radius of each of the following circles : (x – 3)² + (y – 1)² = 9

Answer 1

The general form of the equation of a circle is: 

(x - h)² + (y - k)² = r² 

Where, (h, k) is the centre of the circle. 

r is the radius of the circle. 

Comparing the given equation of circle with general form we get: 

h = 3 , k = 1, r² = 9 

⇒ centre = (3, 1) and radius = 3 units. 

Ans: centre = (3, 1) and radius = 3 units