Question

Find the equation of the circle with the center $(0, 2)$and radius $2$

Answer 1

The equation of a circle with a center $(h, k)$ and radius $r$ is given as

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

Given that the center $(h, k) = (0, 2)$and radius $(r) = 2.$

$\therefore$ the equation of the circle is

$(x - 0)^2 + (y - 2)^2 = 2^2$

$⇒ x^2 + y^2 + 4 - 4 y = 4$

$⇒ x^2 + y^2 - 4y = 0$ (Ans.)