Question

Write the equation of a circle with the center at (-1, -4) that through the point (-1,-1) ​

Answer 1

Equation :

`(x+1)^2 + (y + 4)^2 = 9`

Explanation:

Radius of the circle is the distance between ( -1 , -4 ) and ( -1 , -1)

`radius ,r = √((-1 -- 1)^2 + (-1 --4)^2) }= √(0+9) = 9`

Centre (h , k ) = ( -1 , -4 )

Equation of circle :

`(x-h)^2 + (y - k)^2 = r^2`

`(x+1)^2 + (y + 4)^2 = 3^2\\\\(x+1)^2 + (y + 4)^2 = 9\\\\`