Question

What is the equation of the circle with a center at `(-1 ,2 )` and a radius of `7`?

Answer 1

`(x - (-1))^2 + (y- 2)^2 = 7^2`
or
`(x + 1)^2 + (y- 2)^2 = 49`

Explanation:

The equations of the circle is
`(x - h)^2 + (y- k)^2 = r^2`
where h is the x of the center of the circle and k is the y of the center of the circle, and r is the radius.

(-1,2) radus is 7

h = -1
k = 2
r = 7

plug in the values
`(x - (-1))^2 + (y- 2)^2 = 7^2`
simplify
`(x + 1)^2 + (y- 2)^2 = 49`