Question

find the equation of the circle with centre at (-3,-3) and passing through the point (-3,-6)​

Answer 1

x² + y² + 6x + 6y + 9 = 0

Step-by-step explanation:

The centre of the circle is at (- 3, - 3) and it passes through the point (- 3, - 6)

Then the radius of the circle is

= √{(- 3 + 3)² + (- 3 + 6)²} units

= √(0² + 3²) units

= √9 units

= 3 units

Then the equation of the circle whose centre is at (- 3, - 3) and radius is 3 units, be

(x + 3)² + (y + 3)² = 3²

or, x² + 6x + 9 + y² + 6y + 9 = 9

or, x² + y² + 6x + 6y + 9 = 0