Question

How do you write the equation for a circle with center at (-1, -3) and a radius of 6?

Answer 1

`(x+1)^2+(y+3)^2=36`

Explanation:

The general equation for a circle is `(x-h)^2 + (y-k)^2 = r^2` where the centre if the circle is `(h,k)` and the radius is `r`.

Substituting in the values provided gives us `(x-(-1))^2 + (y-(-3))^2 = 6^2`

`(x+1)^2+(y+3)^2=36`