Question

What is the equation for a circle as follows: center (2, -4) & radius 5?​

Answer 1

`(x-2)^2+(y+4)^2=25`

Explanation:

Equation of a circle:
`(x-h)^2+(y-k)^2=r^2`, where h is the x-coordinate of the center, k is the y-coordinate of the center, and r is the radius of the circle.

The given circle has:

x-coordinate of center: 2

y-coordinate of center: -4

radius: 5

Meaning h = 2, k = -4, r = 5

Substitute into the general eqn.

`(x-2)^2+(y+4)^2=5^2=25`