Question

What is the equation of the circle with a center at `(-1 ,-3 )` and a radius of `7`?

Answer 1

`(x--1)^2+(y--3)^2=49`

Explanation:

Given center (h, k) and radius r

Equation is given `(x-h)^2+(y-k)^2=r^2`
graph of the circle `(x--1)^2+(y--3)^2=49`
graph{(x--1)^2+(y--3)^2=49[-20,20,-12,10]}

God bless...I hope the explanation is useful.