Question

What is the center and radius of the circle with equation(x+1)2+y2=81?

Question 1 options:

center: (1,0) ; radius: 81


center: (-1,0) ; radius: 81


center: (-1,0) ; radius: 9


center: (1,0) ; radius: 9

Answer 1

Answer:Center:(-1,0)

Radius:9

Explanation:

Answer 2

center: (-1,0) ; radius: 9

Explanation:

we know that

The equation of a circle in center radius form is equal to

`(x-h)^2+(y-k)^2=r^2`

where

(h,k) is the center of the circle

r is the radius of the circle

In this problem we have

`(x+1)^2+y^2=81`

so

The center (h,k) is the point
`(-1,0)`

and

the radius

`r^2=81\\r=9\ units`

therefore

center: (-1,0) ; radius: 9