Question

A circle has a radius of 10 units and is centered at (-9,9). What is the equation of this circle? \sqrt{9

square root of, 98, end square write the equation of this circle.

Answer 1

A circle has an equation of a form,

$(x-a)^2+(y-b)^2=r^2$

Where $(a, b)$ is the center and $r$ is the radius.

The coordinates of your circle center are $(a,b)=(-9,9)$ and the radius is $r=\sqrt{98}$, so plug that in,

$(x-(-9))^2+(y-9)^2=\sqrt{98}^2$

and simplify to get the equation,

$(x+9)^2+(y-9)^2=98$

Hope this helps :)