Question

How do you write an equation of a circle with center at (-3,-10), d=24?

Answer 1

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

Where `(a,b)` are the coordinates of the center.

d=2r

24= 2r

`24/2=r`

r=12

Substituting values,

`(x+3)^2+(y+10)^2=144`

`x^2+6x+9+y^2+20y+100=144`

`x^2+y^2+6x+20y+100+9-144=0`

`x^2+y^2+6x+20y-35=0`