Question

What is the equation of the
circle with centre (0,-1) and
radius 4?

Answer 1

Explanation:

Equation of a circle:
`(x-a)^2+(y-b)^2=r^2` with centre
`(a,b)`, radius
`r`.

`(x-0)^2+(y+1)^2=4^2`

`x^2+(y+1)^2=16`