Question

Write the standard equation of the circle in the graph.

A. (x + 3)squared + (y - 2)squared = 9
B. (x - 3)squared + (y + 2)squared = 9
C. (x - 3)squared + (y + 2)squared = 18
D. (x + 3)squared + (y - 2)squared = 18

Answer 1

Answer: B.
`(x-3)^2+(y+2)^2=9`

Explanation:

From the given graph, it can be seen that the center of circle lies at (3,-2).

Radius = distance from the center to the boundary of circle.

=|3-0|=3 units

Standard equation of circle :

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

Then , standard equation of the circle in the graph (having center (3,-2) and radius = 3 units)

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

`(x-3)^2+(y+2)^2=9`

Answer 2

The centre is (a,b) = (3,-2)
The radius is r = 3

The equation of a circle is (x-a)² + (y-b)² = r²

Therefore, the equation of this circle is:
(x-3)²+(y+2)²=9 (B)